publicdata/nist-gov
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
nist-gov/www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception
Scott Williams 4063bef310 Initital commit.
2025-03-05 18:59:57 +00:00

1412 lines
110 KiB
Text
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# ">
<head>
<meta charset="utf-8" /><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.283.2.min.js.LICENSE.txt */
(()=>{var e,t,r={122:(e,t,r)=>{"use strict";r.d(t,{a:()=>i});var n=r(944);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.R)(3);if(!t||"object"!=typeof t)return(0,n.R)(4);const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{if(null===e[a]){r[a]=null;continue}Array.isArray(e[a])&&Array.isArray(t[a])?r[a]=Array.from(new Set([...e[a],...t[a]])):"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.R)(1,e)}return r}catch(e){(0,n.R)(2,e)}}},555:(e,t,r)=>{"use strict";r.d(t,{Vp:()=>c,fn:()=>s,x1:()=>u});var n=r(384),i=r(122);const o={beacon:n.NT.beacon,errorBeacon:n.NT.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){try{const t=c(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}function c(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function u(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.a)(t,o);const r=(0,n.nY)(e);r&&(r.info=a[e])}},217:(e,t,r)=>{"use strict";r.d(t,{D0:()=>m,gD:()=>v,xN:()=>h});r(860).K7.genericEvents;const n="experimental.marks",i="experimental.measures",o="experimental.resources",a=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var s=r(614),c=r(944),u=r(384),l=r(122);const d="[data-nr-mask]",f=()=>{const e={feature_flags:[],experimental:{marks:!1,measures:!1,resources:!1},mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{ajax:{deny_list:void 0,block_internal:!0,enabled:!0,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},get feature_flags(){return e.feature_flags},set feature_flags(t){e.feature_flags=t},generic_events:{enabled:!0,autoStart:!0},harvest:{interval:30},jserrors:{enabled:!0,autoStart:!0},logging:{enabled:!0,autoStart:!0},metrics:{enabled:!0,autoStart:!0},obfuscate:void 0,page_action:{enabled:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,autoStart:!0},performance:{get capture_marks(){return e.feature_flags.includes(n)||e.experimental.marks},set capture_marks(t){e.experimental.marks=t},get capture_measures(){return e.feature_flags.includes(i)||e.experimental.measures},set capture_measures(t){e.experimental.measures=t},capture_detail:!0,resources:{get enabled(){return e.feature_flags.includes(o)||e.experimental.resources},set enabled(t){e.experimental.resources=t},asset_types:[],first_party_domains:[],ignore_newrelic:!0}},privacy:{cookies_enabled:!0},proxy:{assets:void 0,beacon:void 0},session:{expiresMs:s.wk,inactiveMs:s.BB},session_replay:{autoStart:!0,enabled:!1,preload:!1,sampling_rate:10,error_sampling_rate:100,collect_fonts:!1,inline_images:!1,fix_stylesheets:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){a(t)?e.mask_selector="".concat(t,",").concat(d):""===t||null===t?e.mask_selector=d:(0,c.R)(5,t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){a(t)?e.block_selector+=",".concat(t):""!==t&&(0,c.R)(6,t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,c.R)(7,t)}},session_trace:{enabled:!0,autoStart:!0},soft_navigations:{enabled:!0,autoStart:!0},spa:{enabled:!0,autoStart:!0},ssl:void 0,user_actions:{enabled:!0,elementAttributes:["id","className","tagName","type"]}}},g={},p="All configuration objects require an agent identifier!";function m(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function h(e,t){if(!e)throw new Error(p);g[e]=(0,l.a)(t,f());const r=(0,u.nY)(e);r&&(r.init=g[e])}function v(e,t){if(!e)throw new Error(p);var r=m(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}},371:(e,t,r)=>{"use strict";r.d(t,{V:()=>f,f:()=>d});var n=r(122),i=r(384),o=r(154),a=r(324);let s=0;const c={buildEnv:a.F3,distMethod:a.Xs,version:a.xv,originTime:o.WN},u={customTransaction:void 0,disabled:!1,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,onerror:void 0,ptid:void 0,releaseIds:{},appMetadata:{},session:void 0,denyList:void 0,timeKeeper:void 0,obfuscator:void 0,harvester:void 0},l={};function d(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!l[e])throw new Error("Runtime for ".concat(e," was never set"));return l[e]}function f(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");l[e]={...(0,n.a)(t,u),...c},Object.hasOwnProperty.call(l[e],"harvestCount")||Object.defineProperty(l[e],"harvestCount",{get:()=>++s});const r=(0,i.nY)(e);r&&(r.runtime=l[e])}},324:(e,t,r)=>{"use strict";r.d(t,{F3:()=>i,Xs:()=>o,xv:()=>n});const n="1.283.2",i="PROD",o="CDN"},154:(e,t,r)=>{"use strict";r.d(t,{OF:()=>c,RI:()=>i,WN:()=>l,bv:()=>o,gm:()=>a,mw:()=>s,sb:()=>u});var n=r(863);const i="undefined"!=typeof window&&!!window.document,o="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=i?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),s=Boolean("hidden"===a?.document?.visibilityState),c=/iPad|iPhone|iPod/.test(a.navigator?.userAgent),u=c&&"undefined"==typeof SharedWorker,l=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Date.now()-(0,n.t)())},687:(e,t,r)=>{"use strict";r.d(t,{Ak:()=>c,Ze:()=>d,x3:()=>u});var n=r(836),i=r(606),o=r(860),a=r(646);const s={};function c(e,t){const r={staged:!1,priority:o.P3[t]||0};l(e),s[e].get(t)||s[e].set(t,r)}function u(e,t){e&&s[e]&&(s[e].get(t)&&s[e].delete(t),g(e,t,!1),s[e].size&&f(e))}function l(e){if(!e)throw new Error("agentIdentifier required");s[e]||(s[e]=new Map)}function d(e="",t="feature",r=!1){if(l(e),!e||!s[e].get(t)||r)return g(e,t);s[e].get(t).staged=!0,f(e)}function f(e){const t=Array.from(s[e]);t.every((([e,t])=>t.staged))&&(t.sort(((e,t)=>e[1].priority-t[1].priority)),t.forEach((([t])=>{s[e].delete(t),g(e,t)})))}function g(e,t,r=!0){const o=e?n.ee.get(e):n.ee,s=i.i.handlers;if(!o.aborted&&o.backlog&&s){if(r){const e=o.backlog[t],r=s[t];if(r){for(let t=0;e&&t<e.length;++t)p(e[t],r);Object.entries(r).forEach((([e,t])=>{Object.values(t||{}).forEach((t=>{t[0]?.on&&t[0]?.context()instanceof a.y&&t[0].on(e,t[1])}))}))}}o.isolatedBacklog||delete s[t],o.backlog[t]=null,o.emit("drain-"+t,[])}}function p(e,t){var r=e[1];Object.values(t[r]||{}).forEach((t=>{var r=e[0];if(t[0]===r){var n=t[1],i=e[3],o=e[2];n.apply(i,o)}}))}},836:(e,t,r)=>{"use strict";r.d(t,{P:()=>c,ee:()=>u});var n=r(384),i=r(990),o=r(371),a=r(646),s=r(607);const c="nr@context:".concat(s.W),u=function e(t,r){var n={},s={},l={},d=!1;try{d=16===r.length&&(0,o.f)(r).isolatedBacklog}catch(e){}var f={on:p,addEventListener:p,removeEventListener:function(e,t){var r=n[e];if(!r)return;for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)},emit:function(e,r,n,i,o){!1!==o&&(o=!0);if(u.aborted&&!i)return;t&&o&&t.emit(e,r,n);for(var a=g(n),c=m(e),l=c.length,d=0;d<l;d++)c[d].apply(a,r);var p=v()[s[e]];p&&p.push([f,e,r,a]);return a},get:h,listeners:m,context:g,buffer:function(e,t){const r=v();if(t=t||"feature",f.aborted)return;Object.entries(e||{}).forEach((([e,n])=>{s[n]=t,t in r||(r[t]=[])}))},abort:function(){f._aborted=!0,Object.keys(f.backlog).forEach((e=>{delete f.backlog[e]}))},isBuffering:function(e){return!!v()[s[e]]},debugId:r,backlog:d?{}:t&&"object"==typeof t.backlog?t.backlog:{},isolatedBacklog:d};return Object.defineProperty(f,"aborted",{get:()=>{let e=f._aborted||!1;return e||(t&&(e=t.aborted),e)}}),f;function g(e){return e&&e instanceof a.y?e:e?(0,i.I)(e,c,(()=>new a.y(c))):new a.y(c)}function p(e,t){n[e]=m(e).concat(t)}function m(e){return n[e]||[]}function h(t){return l[t]=l[t]||e(f,t)}function v(){return f.backlog}}(void 0,"globalEE"),l=(0,n.Zm)();l.ee||(l.ee=u)},646:(e,t,r)=>{"use strict";r.d(t,{y:()=>n});class n{constructor(e){this.contextId=e}}},908:(e,t,r)=>{"use strict";r.d(t,{d:()=>n,p:()=>i});var n=r(836).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},606:(e,t,r)=>{"use strict";r.d(t,{i:()=>o});var n=r(908);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.d,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.d);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},878:(e,t,r)=>{"use strict";function n(e,t){return{capture:e,passive:!1,signal:t}}function i(e,t,r=!1,i){window.addEventListener(e,t,n(r,i))}function o(e,t,r=!1,i){document.addEventListener(e,t,n(r,i))}r.d(t,{DD:()=>o,jT:()=>n,sp:()=>i})},607:(e,t,r)=>{"use strict";r.d(t,{W:()=>n});const n=(0,r(566).bz)()},566:(e,t,r)=>{"use strict";r.d(t,{LA:()=>s,bz:()=>a});var n=r(154);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n.gm?.crypto||n.gm?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(30))),i.split("").map((e=>"x"===e?o(t,r++).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n.gm?.crypto||n.gm?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(e)));const a=[];for(var s=0;s<e;s++)a.push(o(r,i++).toString(16));return a.join("")}},614:(e,t,r)=>{"use strict";r.d(t,{BB:()=>a,H3:()=>n,g:()=>u,iL:()=>c,tS:()=>s,uh:()=>i,wk:()=>o});const n="NRBA",i="SESSION",o=144e5,a=18e5,s={STARTED:"session-started",PAUSE:"session-pause",RESET:"session-reset",RESUME:"session-resume",UPDATE:"session-update"},c={SAME_TAB:"same-tab",CROSS_TAB:"cross-tab"},u={OFF:0,FULL:1,ERROR:2}},863:(e,t,r)=>{"use strict";function n(){return Math.floor(performance.now())}r.d(t,{t:()=>n})},944:(e,t,r)=>{"use strict";function n(e,t){"function"==typeof console.debug&&console.debug("New Relic Warning: https://github.com/newrelic/newrelic-browser-agent/blob/main/docs/warning-codes.md#".concat(e),t)}r.d(t,{R:()=>n})},284:(e,t,r)=>{"use strict";r.d(t,{t:()=>c,B:()=>s});var n=r(836),i=r(154);const o="newrelic";const a=new Set,s={};function c(e,t){const r=n.ee.get(t);s[t]??={},e&&"object"==typeof e&&(a.has(t)||(r.emit("rumresp",[e]),s[t]=e,a.add(t),function(e={}){try{i.gm.dispatchEvent(new CustomEvent(o,{detail:e}))}catch(e){}}({loaded:!0})))}},990:(e,t,r)=>{"use strict";r.d(t,{I:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},389:(e,t,r)=>{"use strict";function n(e,t=500,r={}){const n=r?.leading||!1;let i;return(...r)=>{n&&void 0===i&&(e.apply(this,r),i=setTimeout((()=>{i=clearTimeout(i)}),t)),n||(clearTimeout(i),i=setTimeout((()=>{e.apply(this,r)}),t))}}function i(e){let t=!1;return(...r)=>{t||(t=!0,e.apply(this,r))}}r.d(t,{J:()=>i,s:()=>n})},289:(e,t,r)=>{"use strict";r.d(t,{GG:()=>o,sB:()=>a});var n=r(878);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.sp)("load",e,t)}function a(e){if(i())return e();(0,n.DD)("DOMContentLoaded",e)}},384:(e,t,r)=>{"use strict";r.d(t,{NT:()=>o,US:()=>l,Zm:()=>a,bQ:()=>c,dV:()=>s,nY:()=>u,pV:()=>d});var n=r(154),i=r(863);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return n.gm.NREUM||(n.gm.NREUM={}),void 0===n.gm.newrelic&&(n.gm.newrelic=n.gm.NREUM),n.gm.NREUM}function s(){let e=a();return e.o||(e.o={ST:n.gm.setTimeout,SI:n.gm.setImmediate,CT:n.gm.clearTimeout,XHR:n.gm.XMLHttpRequest,REQ:n.gm.Request,EV:n.gm.Event,PR:n.gm.Promise,MO:n.gm.MutationObserver,FETCH:n.gm.fetch,WS:n.gm.WebSocket}),e}function c(e,t){let r=a();r.initializedAgents??={},t.initializedAt={ms:(0,i.t)(),date:new Date},r.initializedAgents[e]=t}function u(e){let t=a();return t.initializedAgents?.[e]}function l(e,t){a()[e]=t}function d(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},843:(e,t,r)=>{"use strict";r.d(t,{u:()=>i});var n=r(878);function i(e,t=!1,r,i){(0,n.DD)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),r,i)}},434:(e,t,r)=>{"use strict";r.d(t,{Jt:()=>o,YM:()=>c});var n=r(836),i=r(607);const o="nr@original:".concat(i.W);var a=Object.prototype.hasOwnProperty,s=!1;function c(e,t){return e||(e=n.ee),r.inPlace=function(e,t,n,i,o){n||(n="");const a="-"===n.charAt(0);for(let s=0;s<t.length;s++){const c=t[s],u=e[c];l(u)||(e[c]=r(u,a?c+n:n,i,c,o))}},r.flag=o,r;function r(t,r,n,s,c){return l(t)?t:(r||(r=""),nrWrapper[o]=t,function(e,t,r){if(Object.defineProperty&&Object.keys)try{return Object.keys(e).forEach((function(r){Object.defineProperty(t,r,{get:function(){return e[r]},set:function(t){return e[r]=t,t}})})),t}catch(e){u([e],r)}for(var n in e)a.call(e,n)&&(t[n]=e[n])}(t,nrWrapper,e),nrWrapper);function nrWrapper(){var o,a,l,d;try{a=this,o=[...arguments],l="function"==typeof n?n(o,a):n||{}}catch(t){u([t,"",[o,a,s],l],e)}i(r+"start",[o,a,s],l,c);try{return d=t.apply(a,o)}catch(e){throw i(r+"err",[o,a,e],l,c),e}finally{i(r+"end",[o,a,d],l,c)}}}function i(r,n,i,o){if(!s||t){var a=s;s=!0;try{e.emit(r,n,i,t,o)}catch(t){u([t,r,n,i],e)}s=a}}}function u(e,t){t||(t=n.ee);try{t.emit("internal-error",e)}catch(e){}}function l(e){return!(e&&"function"==typeof e&&e.apply&&!e[o])}},993:(e,t,r)=>{"use strict";r.d(t,{A$:()=>o,ET:()=>a,p_:()=>i});var n=r(860);const i={ERROR:"ERROR",WARN:"WARN",INFO:"INFO",DEBUG:"DEBUG",TRACE:"TRACE"},o={OFF:0,ERROR:1,WARN:2,INFO:3,DEBUG:4,TRACE:5},a="log";n.K7.logging},773:(e,t,r)=>{"use strict";r.d(t,{z_:()=>o,XG:()=>s,TZ:()=>n,rs:()=>i,xV:()=>a});r(154),r(566),r(384);const n=r(860).K7.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},630:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewEvent},782:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewTiming},344:(e,t,r)=>{"use strict";r.d(t,{G4:()=>i});var n=r(614);r(860).K7.sessionReplay;const i={RECORD:"recordReplay",PAUSE:"pauseReplay",REPLAY_RUNNING:"replayRunning",ERROR_DURING_REPLAY:"errorDuringReplay"};n.g.ERROR,n.g.FULL,n.g.OFF},234:(e,t,r)=>{"use strict";r.d(t,{W:()=>o});var n=r(836),i=r(687);class o{constructor(e,t){this.agentIdentifier=e,this.ee=n.ee.get(e),this.featureName=t,this.blocked=!1}deregisterDrain(){(0,i.x3)(this.agentIdentifier,this.featureName)}}},603:(e,t,r)=>{"use strict";r.d(t,{j:()=>K});var n=r(860),i=r(555),o=r(371),a=r(908),s=r(836),c=r(687),u=r(289),l=r(154),d=r(944),f=r(773),g=r(384),p=r(344);const m=["setErrorHandler","finished","addToTrace","addRelease","recordCustomEvent","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start",p.G4.RECORD,p.G4.PAUSE,"log","wrapLogger"],h=["setErrorHandler","finished","addToTrace","addRelease"];var v=r(863),b=r(614),y=r(993);var w=r(646),R=r(434);const A=new Map;function E(e,t,r,n){if("object"!=typeof t||!t||"string"!=typeof r||!r||"function"!=typeof t[r])return(0,d.R)(29);const i=function(e){return(e||s.ee).get("logger")}(e),o=(0,R.YM)(i),a=new w.y(s.P);a.level=n.level,a.customAttributes=n.customAttributes;const c=t[r]?.[R.Jt]||t[r];return A.set(c,a),o.inPlace(t,[r],"wrap-logger-",(()=>A.get(c))),i}function _(){const e=(0,g.pV)();m.forEach((t=>{e[t]=(...r)=>function(t,...r){let n=[];return Object.values(e.initializedAgents).forEach((e=>{e&&e.api?e.exposed&&e.api[t]&&n.push(e.api[t](...r)):(0,d.R)(38,t)})),n.length>1?n:n[0]}(t,...r)}))}const x={};function N(e,t,g=!1){t||(0,c.Ak)(e,"api");const m={};var w=s.ee.get(e),R=w.get("tracer");x[e]=b.g.OFF,w.on(p.G4.REPLAY_RUNNING,(t=>{x[e]=t}));var A="api-",_=A+"ixn-";function N(t,r,n,o){const a=(0,i.Vp)(e);return null===r?delete a.jsAttributes[t]:(0,i.x1)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),j(A,n,!0,o||null===r?"session":void 0)(t,r)}function k(){}m.log=function(e,{customAttributes:t={},level:r=y.p_.INFO}={}){(0,a.p)(f.xV,["API/log/called"],void 0,n.K7.metrics,w),function(e,t,r={},i=y.p_.INFO){(0,a.p)(f.xV,["API/logging/".concat(i.toLowerCase(),"/called")],void 0,n.K7.metrics,e),(0,a.p)(y.ET,[(0,v.t)(),t,r,i],void 0,n.K7.logging,e)}(w,e,t,r)},m.wrapLogger=(e,t,{customAttributes:r={},level:i=y.p_.INFO}={})=>{(0,a.p)(f.xV,["API/wrapLogger/called"],void 0,n.K7.metrics,w),E(w,e,t,{customAttributes:r,level:i})},h.forEach((e=>{m[e]=j(A,e,!0,"api")})),m.addPageAction=j(A,"addPageAction",!0,n.K7.genericEvents),m.recordCustomEvent=j(A,"recordCustomEvent",!0,n.K7.genericEvents),m.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,o.f)(e).customTransaction=(r||"http://custom.transaction")+t,j(A,"setPageViewName",!0)()},m.setCustomAttribute=function(e,t,r=!1){if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return N(e,t,"setCustomAttribute",r);(0,d.R)(40,typeof t)}else(0,d.R)(39,typeof e)},m.setUserId=function(e){if("string"==typeof e||null===e)return N("enduser.id",e,"setUserId",!0);(0,d.R)(41,typeof e)},m.setApplicationVersion=function(e){if("string"==typeof e||null===e)return N("application.version",e,"setApplicationVersion",!1);(0,d.R)(42,typeof e)},m.start=()=>{try{(0,a.p)(f.xV,["API/start/called"],void 0,n.K7.metrics,w),w.emit("manual-start-all")}catch(e){(0,d.R)(23,e)}},m[p.G4.RECORD]=function(){(0,a.p)(f.xV,["API/recordReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.RECORD,[],void 0,n.K7.sessionReplay,w)},m[p.G4.PAUSE]=function(){(0,a.p)(f.xV,["API/pauseReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.PAUSE,[],void 0,n.K7.sessionReplay,w)},m.interaction=function(e){return(new k).get("object"==typeof e?e:{})};const T=k.prototype={createTracer:function(e,t){var r={},i=this,o="function"==typeof t;return(0,a.p)(f.xV,["API/createTracer/called"],void 0,n.K7.metrics,w),g||(0,a.p)(_+"tracer",[(0,v.t)(),e,r],i,n.K7.spa,w),function(){if(R.emit((o?"":"no-")+"fn-start",[(0,v.t)(),i,o],r),o)try{return t.apply(this,arguments)}catch(e){const t="string"==typeof e?new Error(e):e;throw R.emit("fn-err",[arguments,this,t],r),t}finally{R.emit("fn-end",[(0,v.t)()],r)}}}};function j(e,t,r,i){return function(){return(0,a.p)(f.xV,["API/"+t+"/called"],void 0,n.K7.metrics,w),i&&(0,a.p)(e+t,[r?(0,v.t)():performance.now(),...arguments],r?null:this,i,w),r?void 0:this}}function I(){r.e(296).then(r.bind(r,778)).then((({setAPI:t})=>{t(e),(0,c.Ze)(e,"api")})).catch((e=>{(0,d.R)(27,e),w.abort()}))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{T[e]=j(_,e,void 0,g?n.K7.softNav:n.K7.spa)})),m.setCurrentRouteName=g?j(_,"routeName",void 0,n.K7.softNav):j(A,"routeName",!0,n.K7.spa),m.noticeError=function(t,r){"string"==typeof t&&(t=new Error(t)),(0,a.p)(f.xV,["API/noticeError/called"],void 0,n.K7.metrics,w),(0,a.p)("err",[t,(0,v.t)(),!1,r,!!x[e]],void 0,n.K7.jserrors,w)},l.RI?(0,u.GG)((()=>I()),!0):I(),m}var k=r(217),T=r(122);const j={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},I={};var O=r(284);const S=e=>{const t=e.startsWith("http");e+="/",r.p=t?e:"https://"+e};let P=!1;function K(e,t={},r,n){let{init:a,info:c,loader_config:u,runtime:d={},exposed:f=!0}=t;d.loaderType=r;const p=(0,g.pV)();c||(a=p.init,c=p.info,u=p.loader_config),(0,k.xN)(e.agentIdentifier,a||{}),function(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");I[e]=(0,T.a)(t,j);const r=(0,g.nY)(e);r&&(r.loader_config=I[e])}(e.agentIdentifier,u||{}),c.jsAttributes??={},l.bv&&(c.jsAttributes.isWorker=!0),(0,i.x1)(e.agentIdentifier,c);const m=(0,k.D0)(e.agentIdentifier),h=[c.beacon,c.errorBeacon];P||(m.proxy.assets&&(S(m.proxy.assets),h.push(m.proxy.assets)),m.proxy.beacon&&h.push(m.proxy.beacon),_(),(0,g.US)("activatedFeatures",O.B),e.runSoftNavOverSpa&&=!0===m.soft_navigations.enabled&&m.feature_flags.includes("soft_nav")),d.denyList=[...m.ajax.deny_list||[],...m.ajax.block_internal?h:[]],d.ptid=e.agentIdentifier,(0,o.V)(e.agentIdentifier,d),e.ee=s.ee.get(e.agentIdentifier),void 0===e.api&&(e.api=N(e.agentIdentifier,n,e.runSoftNavOverSpa)),void 0===e.exposed&&(e.exposed=f),P=!0}},374:(e,t,r)=>{r.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},860:(e,t,r)=>{"use strict";r.d(t,{$J:()=>u,K7:()=>s,P3:()=>c,XX:()=>i,qY:()=>n,v4:()=>a});const n="events",i="jserrors",o="browser/blobs",a="rum",s={ajax:"ajax",genericEvents:"generic_events",jserrors:i,logging:"logging",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",softNav:"soft_navigations",spa:"spa"},c={[s.pageViewEvent]:1,[s.pageViewTiming]:2,[s.metrics]:3,[s.jserrors]:4,[s.spa]:5,[s.ajax]:6,[s.sessionTrace]:7,[s.softNav]:8,[s.sessionReplay]:9,[s.logging]:10,[s.genericEvents]:11},u={[s.pageViewEvent]:a,[s.pageViewTiming]:n,[s.ajax]:n,[s.spa]:n,[s.softNav]:n,[s.metrics]:i,[s.jserrors]:i,[s.sessionTrace]:o,[s.sessionReplay]:o,[s.logging]:"browser/logs",[s.genericEvents]:"ins"}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>"nr-rum-1.283.2.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.283.2.PROD:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),l=0;l<u.length;l++){var d=u[l];if(d.getAttribute("src")==r||d.getAttribute("data-webpack")==t+o){s=d;break}}if(!s){c=!0;var f={296:"sha512-2Y8GMAOGF658KnXzOZ/v+DlLch8TBFvV0tTNnOy9wrpvtDa1t5CdZMyX+LubTymBlzPp6NUjllBghMCZqXBPmg=="};(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),f[a]&&(s.integrity=f[a])}e[r]=[n];var g=(t,n)=>{s.onerror=s.onload=null,clearTimeout(p);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},p=setTimeout(g.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=g.bind(null,s.onerror),s.onload=g.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://js-agent.newrelic.com/",(()=>{var e={374:0,840:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=self["webpackChunk:NRBA-1.283.2.PROD"]=self["webpackChunk:NRBA-1.283.2.PROD"]||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})(),(()=>{"use strict";i(374);var e=i(944),t=i(344),r=i(566);class n{agentIdentifier;constructor(){this.agentIdentifier=(0,r.LA)(16)}#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}addPageAction(e,t){return this.#e("addPageAction",e,t)}recordCustomEvent(e,t){return this.#e("recordCustomEvent",e,t)}setPageViewName(e,t){return this.#e("setPageViewName",e,t)}setCustomAttribute(e,t,r){return this.#e("setCustomAttribute",e,t,r)}noticeError(e,t){return this.#e("noticeError",e,t)}setUserId(e){return this.#e("setUserId",e)}setApplicationVersion(e){return this.#e("setApplicationVersion",e)}setErrorHandler(e){return this.#e("setErrorHandler",e)}addRelease(e,t){return this.#e("addRelease",e,t)}log(e,t){return this.#e("log",e,t)}}class o extends n{#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}start(){return this.#e("start")}finished(e){return this.#e("finished",e)}recordReplay(){return this.#e(t.G4.RECORD)}pauseReplay(){return this.#e(t.G4.PAUSE)}addToTrace(e){return this.#e("addToTrace",e)}setCurrentRouteName(e){return this.#e("setCurrentRouteName",e)}interaction(){return this.#e("interaction")}wrapLogger(e,t,r){return this.#e("wrapLogger",e,t,r)}}var a=i(860),s=i(217);const c=Object.values(a.K7);function u(e){const t={};return c.forEach((r=>{t[r]=function(e,t){return!0===(0,s.gD)(t,"".concat(e,".enabled"))}(r,e)})),t}var l=i(603);var d=i(687),f=i(234),g=i(289),p=i(154),m=i(384);const h=e=>p.RI&&!0===(0,s.gD)(e,"privacy.cookies_enabled");function v(e){return!!(0,m.dV)().o.MO&&h(e)&&!0===(0,s.gD)(e,"session_trace.enabled")}var b=i(389);class y extends f.W{constructor(e,t,r=!0){super(e.agentIdentifier,t),this.auto=r,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===e.init[this.featureName].autoStart&&(this.auto=!1),this.auto?(0,d.Ak)(e.agentIdentifier,t):this.ee.on("manual-start-all",(0,b.J)((()=>{(0,d.Ak)(e.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator(e)})))}importAggregator(t,r={}){if(this.featAggregate||!this.auto)return;let n;this.onAggregateImported=new Promise((e=>{n=e}));const o=async()=>{let o;try{if(h(this.agentIdentifier)){const{setupAgentSession:e}=await i.e(296).then(i.bind(i,861));o=e(t)}}catch(t){(0,e.R)(20,t),this.ee.emit("internal-error",[t]),this.featureName===a.K7.sessionReplay&&this.abortHandler?.()}try{if(!this.#t(this.featureName,o))return(0,d.Ze)(this.agentIdentifier,this.featureName),void n(!1);const{lazyFeatureLoader:e}=await i.e(296).then(i.bind(i,103)),{Aggregate:a}=await e(this.featureName,"aggregate");this.featAggregate=new a(t,r),t.runtime.harvester.initializedAggregates.push(this.featAggregate),n(!0)}catch(t){(0,e.R)(34,t),this.abortHandler?.(),(0,d.Ze)(this.agentIdentifier,this.featureName,!0),n(!1),this.ee&&this.ee.abort()}};p.RI?(0,g.GG)((()=>o()),!0):o()}#t(e,t){switch(e){case a.K7.sessionReplay:return v(this.agentIdentifier)&&!!t;case a.K7.sessionTrace:return!!t;default:return!0}}}var w=i(630);class R extends y{static featureName=w.T;constructor(e,t=!0){super(e,w.T,t),this.importAggregator(e)}}var A=i(908),E=i(843),_=i(878),x=i(782),N=i(863);class k extends y{static featureName=x.T;constructor(e,t=!0){super(e,x.T,t),p.RI&&((0,E.u)((()=>(0,A.p)("docHidden",[(0,N.t)()],void 0,x.T,this.ee)),!0),(0,_.sp)("pagehide",(()=>(0,A.p)("winPagehide",[(0,N.t)()],void 0,x.T,this.ee))),this.importAggregator(e))}}var T=i(773);class j extends y{static featureName=T.TZ;constructor(e,t=!0){super(e,T.TZ,t),this.importAggregator(e)}}new class extends o{constructor(t){super(),p.gm?(this.features={},(0,m.bQ)(this.agentIdentifier,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(R),this.runSoftNavOverSpa=[...this.desiredFeatures].some((e=>e.featureName===a.K7.softNav)),(0,l.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.R)(21)}get config(){return{info:this.info,init:this.init,loader_config:this.loader_config,runtime:this.runtime}}run(){try{const t=u(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>a.P3[e.featureName]-a.P3[t.featureName])),r.forEach((r=>{if(!t[r.featureName]&&r.featureName!==a.K7.pageViewEvent)return;if(this.runSoftNavOverSpa&&r.featureName===a.K7.spa)return;if(!this.runSoftNavOverSpa&&r.featureName===a.K7.softNav)return;const n=function(e){switch(e){case a.K7.ajax:return[a.K7.jserrors];case a.K7.sessionTrace:return[a.K7.ajax,a.K7.pageViewEvent];case a.K7.sessionReplay:return[a.K7.sessionTrace];case a.K7.pageViewTiming:return[a.K7.pageViewEvent];default:return[]}}(r.featureName).filter((e=>!(e in this.features)));n.length>0&&(0,e.R)(36,{targetFeature:r.featureName,missingDependencies:n}),this.features[r.featureName]=new r(this)}))}catch(t){(0,e.R)(22,t);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,m.Zm)();delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator;return r.ee.get(this.agentIdentifier).abort(),!1}}}({features:[R,k,j],loaderType:"lite"})})()})();</script>
<noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style>
</noscript><script async src="https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script>
<script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("config", "G-CSLL4ZEK4L", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"The Eye of the Beholder: How Lighting Affects Our Color Perception","node_id":"1814551","blog_author":"Megan King","content_type":"Blog entry"});</script>
<meta name="description" content="Remember the social media controversy over the color of a dress? That’s a lighthearted example of how illumination can affect the things we see, but this is serious science" />
<link rel="canonical" href="https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception" />
<link rel="shortlink" href="https://www.nist.gov/node/1814551" />
<meta name="citation_title" content="The Eye of the Beholder: How Lighting Affects Our Color Perception | NIST" />
<meta property="og:site_name" content="NIST" />
<meta property="og:type" content="Article" />
<meta property="og:url" content="https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception" />
<meta property="og:title" content="The Eye of the Beholder: How Lighting Affects Our Color Perception" />
<meta property="og:description" content="Remember the social media controversy over the color of a dress? That’s a lighthearted example of how illumination can affect the things we see, but this is serious science" />
<meta property="og:image" content="https://www.nist.gov/sites/default/files/styles/social/public/images/2023/06/06/1_yoshi_ohno_jane_li_looking_at_computer_lighting_060723.jpeg?itok=Tvi19RYf" />
<meta property="og:image" content="https://www.nist.gov/themes/custom/nist_www/img/homepage/nist_mark.png" />
<meta property="og:image:width" content="2000" />
<meta property="og:image:height" content="1335" />
<meta property="og:image:alt" content="A mirror reflects Yoshi Ohno, seated, and Jane Li, standing, as they view a computer screen showing lighting data." />
<meta property="article:author" content="Megan King" />
<meta property="article:tag" content="optics" />
<meta property="article:published_time" content="2023-06-28T08:00-04:00" />
<meta property="article:modified_time" content="2025-02-11T12:09-05:00" />
<meta name="dcterms.title" content="The Eye of the Beholder: How Lighting Affects Our Color Perception" />
<meta name="dcterms.creator" content="Megan King" />
<meta name="dcterms.description" content="Remember the social media controversy over the color of a dress? That’s a lighthearted example of how illumination can affect the things we see, but this is serious science" />
<meta name="dcterms.publisher" content="Megan King" />
<meta name="dcterms.contributor" content="NIST" />
<meta name="dcterms.date" content="2023-06-28T08:00-04:00" />
<meta name="dcterms.type" content="text" />
<meta name="dcterms.format" content="text/html" />
<meta name="dcterms.identifier" content="https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception" />
<meta name="dcterms.source" content="NIST" />
<meta name="dcterms.created" content="2023-06-28T08:00-04:00" />
<meta name="dcterms.modified" content="2025-02-11T12:09-05:00" />
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:description" content="Remember the social media controversy over the color of a dress? That’s a lighthearted example of how illumination can affect the things we see, but this is serious science" />
<meta name="twitter:site" content="NIST" />
<meta name="twitter:title" content="The Eye of the Beholder: How Lighting Affects Our Color Perception" />
<meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA" />
<meta name="Generator" content="Drupal 10 (https://www.drupal.org)" />
<meta name="MobileOptimized" content="width" />
<meta name="HandheldFriendly" content="true" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="nist_search_modified" class="elastic" content="2025-02-11T12:09:00-05:00" />
<script type="application/ld+json">{
"@context": "https://schema.org",
"@graph": [
{
"@type": "Article",
"@id": "https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception",
"headline": "The Eye of the Beholder: How Lighting Affects Our Color Perception",
"name": "The Eye of the Beholder: How Lighting Affects Our Color Perception",
"description": "Remember the social media controversy over the color of a dress? That’s a lighthearted example of how illumination can affect the things we see, but this is serious science.",
"image": {
"@type": "ImageObject",
"url": "https://www.nist.gov/sites/default/files/styles/social/public/images/2023/06/06/1_yoshi_ohno_jane_li_looking_at_computer_lighting_060723.jpeg?itok=Tvi19RYf",
"width": "2000",
"height": "1335"
},
"datePublished": "2023-06-28T08:00-04:00",
"dateModified": "2025-02-11T12:09-05:00",
"author": {
"@type": "Person",
"@id": "https://www.nist.gov/blogs/taking-measure/authors/megan-king",
"name": "Megan King",
"url": "https://www.nist.gov/blogs/taking-measure/authors/megan-king"
},
"publisher": {
"@type": "GovernmentOrganization",
"@id": "https://www.nist.gov/",
"name": "National Institute of Standards and Technology",
"url": "https://www.nist.gov/"
}
}
]
}</script>
<meta name="nist_search_bundle" class="elastic" content="blog" />
<link rel="icon" href="/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon" />
<title>The Eye of the Beholder: How Lighting Affects Our Color Perception | NIST</title>
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_hKAD9a0878O1Pdb6alKtCmESLiUtQmrBX15rQUvSgOA.css?delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_kGS0ApDpFo-_3JI4Ijxg4RCWlTqsImK3lqH7bCv5v2U.css?delta=1&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<link rel="stylesheet" media="print" href="/sites/default/files/css/css_-IXwLuTUdm8IGHxib8GX8wWKw3LjKsNWSYYskZ5fEGg.css?delta=2&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_RS8YGnRq2Xi5aD-GQC3GKwBe6bOWBBmEmXrb2xB5FMM.css?delta=3&amp;language=en&amp;theme=nist_www&amp;include=eJxNTgsOwyAIvZCpRzKotCNFaYTW9fazW5ctIYRH3i9CWoPJmM3H3x0oSXWV1II9sOD4CUdooUj2mRQiY2Cqq9NTDcvQKr75fmGJwB9t7_2L8WkX3-e2b8DTDd1B2NW_9zS8d75dCiyVZkpuJjZsPsFmNCqpJAIOBTPBFToYDKfsFkarJAe200vFJH8NCqUmSoYvWkVdRQ" />
<script src="/sites/default/files/js/js_GM8kl6wk698qKTTwusj83bCoGHHtOZ1UinjY1sE_Qbk.js?scope=header&amp;delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxdjWsSgyAMhC-kzZEyQSKmAnEApb198dFpx5n8yLfJ7hoaZizaZgHz2_GZO6fqPCNF8u8iQ4a70EXJBUdpmtUavZLFklqIRAeOznOWwhKWpBvDXdhbDq1MHLj1qjeUMKgFK5lMC_YS5-MHnFdDvr8sMDFZTl_EWuvfB7_KbgSb1oX848LTGMhFGWXoNuGa8bmGBQPHFQ7ud-53_gAS9G-N"></script>
</head>
<body class="node-1814551">
<a href="#main-content" class="visually-hidden focusable" data-elastic-exclude>
Skip to main content
</a>
<div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>
<!-- nist-index-ignore-start -->
<section data-elastic-exclude class="usa-banner" aria-label="Official government website">
<div class="usa-accordion">
<header class="usa-banner__header">
<div class="usa-banner__inner">
<div class="grid-col-auto">
<img class="usa-banner__header-flag" src="/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag">
</div>
<div class="grid-col-fill tablet:grid-col-auto">
<p class="usa-banner__header-text">An official website of the United States government</p>
<p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p>
</div>
<button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default">
<span class="usa-banner__button-text">Here’s how you know</span>
</button>
</div>
</header>
<div class="usa-banner__content usa-accordion__content" id="gov-banner-default">
<div class="grid-row grid-gap-lg">
<div class="usa-banner__guidance tablet:grid-col-6">
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true">
<div class="usa-media-block__body">
<p>
<strong>Official websites use .gov</strong>
<br/>
A <strong>.gov</strong> website belongs to an official government organization in the United States.
</p>
</div>
</div>
<div class="usa-banner__guidance tablet:grid-col-6">
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true">
<div class="usa-media-block__body">
<p>
<strong>Secure .gov websites use HTTPS</strong>
<br/>
A <strong>lock</strong> ( <span class="icon-lock">
<svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false">
<title id="banner-lock-title">Lock</title>
<desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg>
</span>
) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
</p>
</div>
</div>
</div>
</div>
</div>
</section>
<!-- nist-index-ignore-end -->
<div data-elastic-exclude>
<!-- nist-index-ignore-start -->
<div class="nist-print-header" style="display:none;">
<p class="nist-print-header__url">https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception</p>
<img class="nist-print-header__logo" width="289" height="38" src="/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology" />
</div>
<div class="usa-overlay"></div>
<header class="usa-header nist-header--www nist-header--minimal" role="banner">
<div class="usa-navbar">
<div class="usa-logo flex-fill">
<a href="/" title="National Institute of Standards and Technology" aria-label="Home">
<img src="/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px" />
</a>
</div>
<div class="usa-header__right grid-row flex-auto">
<div class="grid-col-fill nist-header__search-group">
<form class="usa-search usa-search--small"
accept-charset="UTF-8"
action="/search"
id="search_form"
method="get">
<div role="search">
<label class="usa-sr-only" for="search-form">Search NIST</label>
<input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128">
<button class="usa-button" type="submit"><img src="/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button>
</div>
</form>
</div>
<div class="grid-col-auto padding-left-1">
<button class="usa-menu-btn">Menu</button>
</div>
</div>
</div>
<nav aria-label="Primary navigation" class="usa-nav">
<div class="usa-nav__inner">
<button class="usa-nav__close">Close</button>
<ul class="usa-nav__primary usa-accordion">
<li class="usa-nav__primary-item">
<a class="usa-nav__link" href="/publications">Publications</a>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-2"><span>What We Do</span></button>
<div id="primary_menu-2" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/topics" class="usa-nav__link">All Topics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/advanced-communications" class="usa-nav__link">Advanced communications</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/bioscience" class="usa-nav__link">Bioscience</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/buildings-construction" class="usa-nav__link">Buildings and construction</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/chemistry" class="usa-nav__link">Chemistry</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/cybersecurity" class="usa-nav__link">Cybersecurity</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/electronics" class="usa-nav__link">Electronics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/energy" class="usa-nav__link">Energy</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/environment" class="usa-nav__link">Environment</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/fire" class="usa-nav__link">Fire</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/forensic-science" class="usa-nav__link">Forensic science</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/health" class="usa-nav__link">Health</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/information-technology" class="usa-nav__link">Information technology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/infrastructure" class="usa-nav__link">Infrastructure</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/manufacturing" class="usa-nav__link">Manufacturing</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/materials" class="usa-nav__link">Materials</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/metrology" class="usa-nav__link">Metrology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/nanotechnology" class="usa-nav__link">Nanotechnology</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/neutron-research" class="usa-nav__link">Neutron research</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/performance-excellence" class="usa-nav__link">Performance excellence</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/physics" class="usa-nav__link">Physics</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/public-safety" class="usa-nav__link">Public safety</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/quantum-information-science" class="usa-nav__link">Quantum information science</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/resilience" class="usa-nav__link">Resilience</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/standards" class="usa-nav__link">Standards</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/transportation" class="usa-nav__link">Transportation</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs &amp; Major Programs</span></button>
<div id="primary_menu-3" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/adlp" class="usa-nav__link">Assoc Director of Laboratory Programs</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories" class="usa-nav__link">Laboratories</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/ctl" class="usa-nav__link">Communications Technology Laboratory</a>
</li>
<li>
<a href="/el" class="usa-nav__link">Engineering Laboratory</a>
</li>
<li>
<a href="/itl" class="usa-nav__link">Information Technology Laboratory</a>
</li>
<li>
<a href="/mml" class="usa-nav__link">Material Measurement Laboratory</a>
</li>
<li>
<a href="/pml" class="usa-nav__link">Physical Measurement Laboratory</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/user-facilities" class="usa-nav__link">User Facilities</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a>
</li>
<li>
<a href="/cnst" class="usa-nav__link">CNST NanoFab</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories/projects-programs" class="usa-nav__link">Research Projects</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/laboratories/tools-instruments" class="usa-nav__link">Tools &amp; Instruments</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/major-programs" class="usa-nav__link">Major Programs</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a>
</li>
<li>
<a href="/chips" class="usa-nav__link">CHIPS for America Initiative</a>
</li>
<li>
<a href="/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a>
</li>
<li>
<a href="/oam" class="usa-nav__link">Office of Advanced Manufacturing</a>
</li>
<li>
<a href="/spo" class="usa-nav__link">Special Programs Office</a>
</li>
<li>
<a href="/tpo" class="usa-nav__link">Technology Partnerships Office</a>
</li>
</ul>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services &amp; Resources</span></button>
<div id="primary_menu-4" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/content/standards-measurements" class="usa-nav__link">Standards and Measurements</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/calibrations" class="usa-nav__link">Calibration Services</a>
</li>
<li>
<a href="/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a>
</li>
<li>
<a href="/nist-quality-system" class="usa-nav__link">Quality System</a>
</li>
<li>
<a href="/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a>
</li>
<li>
<a href="/sri" class="usa-nav__link">Standard Reference Instruments (SRIs)</a>
</li>
<li>
<a href="/standardsgov" class="usa-nav__link">Standards.gov</a>
</li>
<li>
<a href="/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a>
</li>
<li>
<a href="/pml/owm" class="usa-nav__link">Office of Weights and Measures</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/services-resources/software" class="usa-nav__link">Software</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/data" class="usa-nav__link">Data</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a>
</li>
<li>
<a href="https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a>
</li>
<li>
<a href="/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a>
</li>
<li>
<a href="/srd" class="usa-nav__link">Standard Reference Data (SRD)</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="https://shop.nist.gov/" class="usa-nav__link">Storefront</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/tpo" class="usa-nav__link">License &amp; Patents</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/nist-research-library" class="usa-nav__link">NIST Research Library</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News &amp; Events</span></button>
<div id="primary_menu-5" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/news-events/news" class="usa-nav__link">News</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/news-events/events" class="usa-nav__link">Events</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/blogs" class="usa-nav__link">Blogs</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/feature-stories" class="usa-nav__link">Feature Stories</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/awards" class="usa-nav__link">Awards</a>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/video-gallery" class="usa-nav__link">Video Gallery</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/image-gallery" class="usa-nav__link">Image Gallery</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/pao/media-contacts" class="usa-nav__link">Media Contacts</a>
</li>
</ul>
</div>
</div>
</div>
</li>
<li class="usa-nav__primary-item">
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button>
<div id="primary_menu-6" class="usa-nav__submenu usa-megamenu">
<div class="grid-row">
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/about-nist" class="usa-nav__link">About Us</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/director/leadership" class="usa-nav__link">Leadership</a>
</li>
<li>
<a href="/director/nist-organization-structure" class="usa-nav__link">Organization Structure</a>
</li>
<li>
<a href="/about-nist/budget-planning" class="usa-nav__link">Budget &amp; Planning</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/about-nist/contact-us" class="usa-nav__link">Contact Us</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/about-nist/visit" class="usa-nav__link">Visit</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/careers" class="usa-nav__link">Careers</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="/iaao/academic-affairs-office" class="usa-nav__link">Student programs</a>
</li>
</ul>
</li>
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
<li class="usa-nav__submenu-item">
<a href="/about-nist/work-nist" class="usa-nav__link">Work with NIST</a>
</li>
<li class="usa-nav__submenu-item">
<a href="/history" class="usa-nav__link">History</a>
<ul class="usa-nav__submenu-list">
<li>
<a href="http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a>
</li>
<li>
<a href="/nist-museum" class="usa-nav__link">NIST Museum</a>
</li>
<li>
<a href="/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a>
</li>
</ul>
</li>
<li class="usa-nav__submenu-item">
<a href="/education" class="usa-nav__link">Educational Resources</a>
</li>
</ul>
</div>
</div>
</div>
</li>
</ul>
</div>
</nav>
</header>
<!-- nist-index-ignore-end -->
</div>
<div class="grid-container">
</div>
<div
id="block-nist-www-content" class="nist-block"
>
<section
class="nist-page__content usa-section clearfix"
>
<a id="main-content" tabindex="-1"></a>
<div
class="nist-page__region nist-page__region--content-top-full"
>
<div
class="nist-block"
>
<div class="entity-reference">
<div class="nist-blog-header nist-blog-header--purple nist-blog-header--inner">
<div class="nist-blog-header__bkgrd">
<div class="nist-blog-header__main grid-container">
<div class="grid-row">
<h2 class="nist-blog-header__title">
<a href="/blogs/taking-measure"> Taking Measure
</a>
</h2>
<div class="nist-blog-header__tagline">
<p class="text">Just a Standard Blog</p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="grid-container margin-top-4">
<div
class="nist-page__region nist-page__region--content-top"
>
<div
class="nist-block"
>
<h1 class="nist-page__title">The Eye of the Beholder: How Lighting Affects Our Color Perception</h1>
</div>
<div
class="font-body-md"
>
<div class="daterange"><time datetime="2023-06-28T12:00:00Z">June 28, 2023</time>
</div>
</div>
<div
class="nist-block"
>
<span>By: </span>
<a href="/blogs/taking-measure/authors/megan-king" hreflang="en">Megan King</a>
</div>
<div
class="nist-block"
>
<!-- nist-index-ignore-start -->
<div data-elastic-exclude class="nist-block nist-social__wrapper">
<h2 class="nist-social__title">Share</h2>
<div class="social-media-sharing">
<div class="nist-social__wrapper--share">
<div>
<a target="_blank" rel="noopener" href="https://www.facebook.com/share.php?u=https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception"
title="Facebook" class="nist-social nist-social--facebook-gray">
<span>Facebook</span>
</a>
</div>
<div>
<a target="_blank" rel="noopener" href="https://www.linkedin.com/shareArticle?mini=true&amp;url=https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception&amp;source=https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception"
title="Linkedin" class="nist-social nist-social--linkedin-gray">
<span>Linkedin</span>
</a>
</div>
<div>
<a target="_blank" rel="noopener" href="https://x.com/intent/tweet?url=https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception&amp;status=https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception"
title="X.com" class="nist-social nist-social--x-gray">
<span>X.com</span>
</a>
</div>
<div>
<a href="mailto:?subject=NIST.gov&amp;body=Check out this site https://www.nist.gov/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception"
title="Email" class="nist-social nist-social--envelope-gray">
<span>Email</span>
</a>
</div>
</div>
</div>
</div>
<!-- nist-index-ignore-end -->
</div>
</div>
</div>
<div class="grid-container margin-top-4">
<div class="grid-row grid-gap-6">
<div
class="nist-page__region nist-page__region--content tablet-lg:grid-col-8"
>
<div
class="nist-block"
>
<div class="text-with-summary">
<figure class=" align-center nist-image--lightbox nist-image" role="group">
<div data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2023/06/06/1_yoshi_ohno_jane_li_looking_at_computer_lighting_060723.jpeg?itok=84ipw6u7" data-media-id="676631">
<img alt="A mirror reflects Yoshi Ohno, seated, and Jane Li, standing, as they view a computer screen showing lighting data. " height="1335" loading="lazy" src="/sites/default/files/images/2023/06/06/1_yoshi_ohno_jane_li_looking_at_computer_lighting_060723.jpeg" typeof="foaf:Image" width="2000">
</div>
<figcaption class="nist-image__caption">NIST researchers Yoshi Ohno and Jane Li demonstrate different types of lighting in their lab on NIST’s campus in Gaithersburg, Maryland.<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
R. Wilson/NIST
</div></figcaption>
</figure>
<p>If you’ve ever tried on clothing at a store only to have it look completely different at home, you know how much our eyes depend on lighting to help us see colors.&nbsp;</p><p>We also all interpret colors a little differently, even with the same lighting. &nbsp;&nbsp;</p><p>Remember the <a href="https://slate.com/technology/2017/04/heres-why-people-saw-the-dress-differently.html">social media controversy</a> over the color of a dress that everyone seemed to have a different opinion on? That’s a lighthearted example of how illumination can affect the things we see, but this is serious science. How our eyes see color under different conditions can affect such things as how health professionals read medical imaging scans.&nbsp;</p><p>NIST researchers Yoshi Ohno and Jane Li study how LED lights affect our perception of color. Their research could someday inspire new international standards for the color quality of the lighting we use every day.&nbsp;</p><h2>The Science of Color&nbsp;</h2><p>On a recent Friday afternoon, I visited the lighting lab at NIST’s campus in Gaithersburg, Maryland. Yoshi started by taking me on a tour of the space. With fluffy rugs and colorful artwork on the walls, it’s much nicer than any other government office I’ve worked in or visited!&nbsp;</p><p>On the ceiling, the lab features a lighting fixture that can be changed with the press of a button on a remote. The room simulates how lighting would look in a typical living room.&nbsp;</p>
<figure class=" align-center nist-image--lightbox nist-image" role="group">
<div data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2023/06/06/2_yoshi_ohno_talking_in_lighting_lab_060723.jpg?itok=u75NJh03" data-media-id="676641">
<img alt="Yoshi Ohno speaks to Megan King in a small room with a specialized ceiling light fixture showing different colors of light. " height="1001" loading="lazy" src="/sites/default/files/images/2023/06/06/2_yoshi_ohno_talking_in_lighting_lab_060723.jpg" typeof="foaf:Image" width="1500">
</div>
<figcaption class="nist-image__caption">NIST researcher Yoshi Ohno’s lab has different types of lighting so he can study how our eyes perceive color in different types of lighting conditions.<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
R. Wilson/NIST
</div></figcaption>
</figure>
<p>Yoshi explained to me that warm colors (orangish and reddish colors) and cool colors (bluish or greenish colors) create different lighting effects. It’s especially pronounced when you look at skin.&nbsp;</p><p>He clicked the remote, and a harsh, bright light came over us. I looked in the mirror at my washed-out face.&nbsp;</p><p>He clicked the remote again, and a pleasant, orange hue began to illuminate the room. He had me look at my face in the mirror. Much better. (As a nearly middle-aged person with an increasingly complex skin-care routine as I age, I’m happy this scientific advancement in lighting exists!)&nbsp;</p><p>The way in which colors of objects appear under a particular light is called color rendering.&nbsp;</p><p>Interestingly, Yoshi explained that people who live in colder climates generally prefer warmer-colored lighting. People who live in warmer climates prefer cooler-colored lighting. I guess everything is a balance!&nbsp;</p><h2>Eyes on the Colorful Prize&nbsp;</h2>
<figure class=" align-right nist-image--lightbox nist-image" role="group">
<div data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2023/06/06/3_jane_li_megan_king_experiment_in_led_lab_060723.jpeg.jpg?itok=P89h8dLX" data-media-id="676656">
<img alt="Megan King wears a black mask as she looks into a lighting test device, with Jane Li standing in the background. " height="480" loading="lazy" src="/sites/default/files/styles/480_x_480_limit/public/images/2023/06/06/3_jane_li_megan_king_experiment_in_led_lab_060723.jpeg.jpg?itok=yWGwOKil" typeof="foaf:Image" width="320">
</div>
<figcaption class="nist-image__caption">NIST researcher Jane Li (back) tests my color perception in different lighting conditions in her lab.<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
R. Wilson/NIST
</div></figcaption>
</figure>
<p>I’m not just here for a tour though. I’ve signed up to be a participant in an experiment on how different types of lighting conditions affect our perception of colors. NIST employees, interns, and even family and friends of our employees sign up to participate. The only requirement is to be an adult with normal color vision (glasses or contacts are fine).&nbsp;</p><p>Jane then showed me to the booth where my color perception would be put to the test. First, I had to pass a test of my color vision and an additional test to check that the blue light filter on my glasses wouldn’t impact my color vision. I passed both with, um, flying colors. &nbsp;&nbsp;</p><p>The room was dark so as not to interfere with my vision. I sat in a chair in front of a viewing booth divided in half. I had to put my nose directly up against the cardboard center line of the booth (while wearing a mask for cleanliness). The two sides of the booth had the same background color (gray) but different lighting levels.&nbsp;</p><p>After a period of adaptation, the brightness I perceived on the two sides gradually converged. After adapting my eyes to the gray background, Jane placed one square sample of a certain color on the one side of the booth (with less light). The other side had more light, and she placed a board with 20 similar color samples there. I had less than 10 seconds to identify the closest match from the 20 samples. The time limit prevented my eyes from adapting to the sample color other than gray. She switched colors, and we started again.&nbsp;</p><p>We did this for several rounds in different types of lighting. I stared at the gray background for a few minutes in between rounds to reset my eyes. I felt pressure to choose a color match quickly. It was like when the eye doctor asks “A” or “B” or “1” or “2” during your eye exam. But it was also a fun challenge.&nbsp;</p><p>I told Jane that yellow was a particularly challenging color for me to match. The yellows all looked like the tiniest bit of difference in shades of a highlighter to me. That may be one way my color perception is different from others’.&nbsp;</p>
<figure class=" align-center nist-image--lightbox nist-image" role="group">
<div data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2023/06/06/4_led_lighting_experiment_light_booth_060723.jpg?itok=E56nw3OB" data-media-id="676661">
<img alt="Megan King looks into a lighting test booth at a grid of orange-hued color samples. " height="721" loading="lazy" src="/sites/default/files/images/2023/06/06/4_led_lighting_experiment_light_booth_060723.jpg" typeof="foaf:Image" width="1080">
</div>
<figcaption class="nist-image__caption">I had just a few seconds to match up colors in an experiment to test my color perception under different lighting conditions.<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
R. Wilson/NIST
</div></figcaption>
</figure>
<p>The second round was easier. We used just one side of the booth, and Jane handed me the same square and coordinating color card with 20 shades of that color. I had to match them up without a time limit. This was much more enjoyable — like matching paint colors to a sample at the home improvement store. I felt like my answers were closer to “right” than in the speed round.&nbsp;</p><p>But Jane explained to me after the experiment that there is no “right” answer, but there are answers they expect you to give based on the lighting in any given round. Jane said my answers were fairly close to what she expected.&nbsp;</p><p>I’m one of 20 adults who will do the same experiment over the course of the month. I asked Jane how they figure out the demographic breakdown of their participants. Jane said in her previous research, she found no real difference in color perception based on gender. Some other studies have shown women can outperform men in <a href="https://www.smithsonianmag.com/smart-news/men-and-women-see-things-differently-literally-180954815/">distinguishing subtle color differences</a>. &nbsp;&nbsp;</p><p>Jane explained that there is some difference in color perception based on age, and the international standard for lighting is based on the eyes of a 32-year-old. While I’m a bit older than that at 39, I’m still close enough to the target demographic to offer useful data!&nbsp;</p><h2>Setting the Standard for Modern Lighting &nbsp;</h2><p>One of the measurements used to test lighting is the Color Rendering Index (CRI), which measures how light affects the appearance of colors in relation to an incandescent lamp or daylight. If a light has a high CRI, the colors you look at under that light should look close to how they appear under an incandescent bulb or outside. &nbsp;</p><p>The challenge, Yoshi explained, is that the CRI doesn’t match up to what people perceive.&nbsp;</p>
<figure class=" align-left nist-image--lightbox nist-image" role="group">
<div data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2023/06/06/5_jane_li_at_desk_in_lab_060723.jpg?itok=4WZKjsBn" data-media-id="676651">
<img alt="Jane Li poses at her desk with color samples in the background." height="480" loading="lazy" src="/sites/default/files/styles/480_x_480_limit/public/images/2023/06/06/5_jane_li_at_desk_in_lab_060723.jpg?itok=uyCjI4X9" typeof="foaf:Image" width="480">
</div>
<figcaption class="nist-image__caption">NIST postdoctoral researcher Jane Li will use the results of the color perception study to create statistical models that could influence future international standards for lighting.<div class="nist-image__credit">
<span class="nist-image__credit-label">Credit:</span>
R. Wilson/NIST
</div></figcaption>
</figure>
<p>When Yoshi showed me my face under that harsh lighting, that was a 95 on the CRI. The much more flattering lighting was only a 70 on the CRI. This is not necessarily surprising, as the standard was set 50 years ago before LED lighting was invented.</p><p>This has been the focus of Yoshi’s research — understanding the gap between the standards and people’s perception and updating those international standards to match what people see.&nbsp;</p><p>Jane will use the results of the study to create statistical models that could influence future international standards for lighting. Organizations such as the <a href="https://blog.ansi.org/">American National Standards Institute (ANSI)</a> and the <a href="https://cie.co.at/">International Commission on Illumination (CIE)</a> publish standards on everything from the color range of white light that is acceptable for your home to the methods of evaluating color rendering (like CRI) that are suitable for various lighting uses.&nbsp;</p><p>I’m glad to know I may play a very small part in updating lighting standards to fit our modern preferences and today’s lighting technology.&nbsp;</p><p>NIST’s research is probably already reflected in your home or workplace’s lights, and this research may help illuminate everyone’s path toward better lighting in the years to come.</p>
</div>
</div>
<div
class="nist-block"
>
<div class="nist-tags">
<a href="/blogs/taking-measure/categories/249051">Metrology</a>,
<a href="/blogs/taking-measure/categories/249106">Optical / photometry / laser metrology</a>,
<a href="/blogs/taking-measure/categories/249241">Physics</a>,
<a href="/blogs/taking-measure/categories/249276">Optical physics and communications</a>,
<a href="/blogs/taking-measure/categories/249341">Standards</a> and
<a href="/blogs/taking-measure/categories/249371">Documentary standards</a></div>
</div>
<div
class="nist-block"
>
<h2
class="nist-block__title"
>About the author</h2>
<div class="nist-field nist-field--label-hidden entity-reference">
<div class="nist-field__items">
<div class="nist-field__item">
<article
about="/blogs/taking-measure/authors/megan-king" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/authors/megan-king" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2023/02/03/profile_pic.jpg?itok=o4iiq7DH" width="67" height="100" alt="Megan King poses outdoors for a black-and-white head shot. " typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/authors/megan-king"><span>Megan King</span>
</a></h3>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"><p>Megan King is a writer-editor at NIST and edits the Taking Measure blog. After graduating from John Carroll University, she began her career as a newspaper journalist, covering county fairs and school board meetings. Megan has worked in various communications roles in the government for more than 15 years, including as a content manager and strategist. Outside of work, Megan coaches beginner ice skaters, cheers on Pittsburgh sports teams, and knits.</p></div>
</div>
</div>
</article>
</div>
</div>
</div>
</div>
<div
class="views-element-container nist-block no-print"
>
<h2
class="nist-block__title"
>Related posts</h2>
<div><div class="js-view-dom-id-09f95ce1ec01c2fec38f1f6c822a26e3d0f94b97c92d262a9204d9695c46f6c7">
<div>
<article
about="/blogs/taking-measure/high-flying-science-how-and-why-we-sent-refrigerator-halfway-space" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/high-flying-science-how-and-why-we-sent-refrigerator-halfway-space" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2025/01/23/ephraim_gau_tes_balloon_in_air_012125.JPG?itok=vkGGerAo" width="75" height="100" alt="A rectangular box coated with reflective foil hangs from cables over a parking lot." typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/high-flying-science-how-and-why-we-sent-refrigerator-halfway-space"><span>High-Flying Science: How and Why We Sent a Refrigerator Halfway to Space</span>
</a></h3>
<div class="nist-teaser__date">
<div class="daterange"><time datetime="2025-02-12T12:00:00Z">February 12, 2025</time>
</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> NIST-developed tools can study the remnants of the Big Bang and more, and now researchers are working to launch these tools high above the Earth’s atmosphere —
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/blogs/taking-measure/5-concepts-can-help-you-understand-quantum-mechanics-and-technology-without" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/5-concepts-can-help-you-understand-quantum-mechanics-and-technology-without" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2023/10/16/tara_fortier_working_in_lab_october_2023.jpg?itok=RkM9HePP" width="100" height="67" alt="A researcher wearing safety glasses reaches into a box of circuitry and other equipment, which emits a green glow. " typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/5-concepts-can-help-you-understand-quantum-mechanics-and-technology-without"><span>5 Concepts Can Help You Understand Quantum Mechanics and Technology — Without Math!</span>
</a></h3>
<div class="nist-teaser__date">
<div class="daterange"><time datetime="2025-02-05T12:00:00Z">February 5, 2025</time>
</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> Quantum is everywhere, and you can understand the basic quirks of life at the quantum level … no math required.
</div>
</div>
</div>
</article>
</div>
<div>
<article
about="/blogs/taking-measure/safer-skies-fewer-fires-10-ways-nist-impacts-your-daily-life" class="nist-teaser"
>
<div class="nist-teaser__image">
<div class="entity-reference"> <a href="/blogs/taking-measure/safer-skies-fewer-fires-10-ways-nist-impacts-your-daily-life" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2024/12/12/2024_EndofYearBlogPost_960x600_v1.png?itok=qqCEC65E" width="100" height="63" alt="Photos of everyday objects like an iron, a gas can and a laptop along with high-tech items like an atomic clock and a mass balance. Label reads: 10 Ways NIST Impacts Your Daily Life. " typeof="foaf:Image" />
</a>
</div>
</div>
<div class="nist-teaser__content-wrapper">
<header>
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/safer-skies-fewer-fires-10-ways-nist-impacts-your-daily-life"><span>From Safer Skies to Fewer Fires: 10 Ways NIST Impacts Your Daily Life</span>
</a></h3>
<div class="nist-teaser__date">
<div class="daterange"><time datetime="2024-12-19T12:00:00Z">December 19, 2024</time>
</div>
</div>
</header>
<div class="nist-teaser__content">
<div class="text-with-summary"> If you’ve ever had a medical test, flown on an airplane, or needed to check the time, NIST’s work affects your life every day.
</div>
</div>
</div>
</article>
</div>
</div>
</div>
</div>
<div
class="nist-block no-print"
>
<h2
class="nist-block__title"
>Comments</h2>
<section>
<h2>Add new comment</h2>
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_Lx5yvw0vUi4TN7C0L-5Rdrp4Q049mXEKn-dXREWOtBs.css?delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxLzCvJTMov0U-E0Hpp-UW5OsmJBSXJGYn6SYnFqTppmTklqUX6KUWlBYk5ehAeAD47FNs&amp;exclude=eJx1UAuuwyAMuxAdR0IBsi5bIBWfdb39QrunVZOeRFDsWI7BQ3i4JnoW67-9u1fj_xlRkGxmkZnRQQbeGoVqfwmTqTZ3JeWirJkFomtFbSjPdoZjXKkhpaXIE-0vMSLsXLthQt0s7KG4JNFGquDVmCk_TN1qw6QJK-56O7N44HM_fazsDSFi-YNuXdez-oSHBF9tLLCx9AX48oHmSbhWu98XDdMZTV0gaWUr_tprgKaUBAJ2CSPByEbBMGzSm9PwQZ9XNisZg_Bh6O49LSrP_bCeBp4G_kZLFIqMH3oD_KWsjg" />
<form class="comment-comment-node-blog-form comment-form usa-form antibot" novalidate="novalidate" data-drupal-selector="comment-form" data-action="/comment/reply/node/1814551/comment_node_blog" action="/antibot" method="post" id="comment-form" accept-charset="UTF-8">
<noscript>
<div class="antibot-no-js antibot-message antibot-message-warning">You must have JavaScript enabled to use this form.</div>
</noscript>
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-name js-form-item-name">
<label for="edit-name" class="usa-label">
Your name
</label>
<input data-drupal-default-value="Anonymous" data-drupal-selector="edit-name" type="text" id="edit-name" name="name" value="" size="30" maxlength="60" class="form-text usa-input" />
</div>
<input data-drupal-selector="form-ucpm9vaibdntivcmbvcfi-ey-eum-wac3ofl9volseu" type="hidden" name="form_build_id" value="form-ucPm9VaIBdNtIVcmbvCFI_eY_Eum-WAC3oFL9VolseU" class="usa-input" /><input data-drupal-selector="edit-comment-comment-node-blog-form" type="hidden" name="form_id" value="comment_comment_node_blog_form" class="usa-input" /><input data-drupal-selector="edit-antibot-key" type="hidden" name="antibot_key" value="" class="usa-input" /><div class="field--type-text-long field--name-comment-body field--widget-text-textarea js-form-wrapper form-wrapper" data-drupal-selector="edit-comment-body-wrapper" id="edit-comment-body-wrapper"> <div class="js-text-format-wrapper js-form-item form-item">
<div class="form-item js-form-item form-type-textarea js-form-type-textarea form-item-comment-body-0-value js-form-item-comment-body-0-value">
<label for="edit-comment-body-0-value" class="usa-label form-required">
Comment
<span class="usa-label--required"> <span class="usa-sr-only">Required</span>*</span></label>
<div class="form-textarea-wrapper">
<textarea class="js-text-full text-full form-textarea required usa-textarea resize-vertical" data-entity_embed-host-entity-langcode="en" data-media-embed-host-entity-langcode="en" data-drupal-selector="edit-comment-body-0-value" id="edit-comment-body-0-value" name="comment_body[0][value]" rows="5" cols="60" placeholder="" required="required" aria-required="true"></textarea>
</div>
</div>
<div class="js-filter-wrapper filter-wrapper hidden js-form-wrapper form-wrapper" data-drupal-selector="edit-comment-body-0-format" id="edit-comment-body-0-format"><div class="js-filter-guidelines filter-guidelines js-form-wrapper form-wrapper" data-drupal-selector="edit-comment-body-0-format-guidelines" id="edit-comment-body-0-format-guidelines"><div data-drupal-format-id="plain_text">
<h4>Plain text</h4>
<ul>
<li>No HTML tags allowed.</li>
<li>Web page addresses and email addresses turn into links automatically.</li>
<li>Lines and paragraphs break automatically.</li>
</ul>
</div>
</div>
</div>
</div>
</div>
<fieldset data-drupal-selector="edit-captcha" class="captcha captcha-type-challenge--image">
<legend class="captcha__title js-form-required form-required">
CAPTCHA
</legend>
<div class="captcha__element">
<input data-drupal-selector="edit-captcha-sid" type="hidden" name="captcha_sid" value="652142781" class="usa-input" /><input data-drupal-selector="edit-captcha-token" type="hidden" name="captcha_token" value="5mC_GcR3wAjbDow3r5bKfrDAZyQYZo1m0WGBDRMrCiI" class="usa-input" /><div class="captcha__image-wrapper js-form-wrapper form-wrapper" data-drupal-selector="edit-captcha-image-wrapper" id="edit-captcha-image-wrapper"><img data-drupal-selector="edit-captcha-image" src="/image-captcha-generate/652142781/1741077854" width="180" height="60" alt="Image CAPTCHA" title="Image CAPTCHA" loading="lazy" typeof="foaf:Image" />
</div>
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-captcha-response js-form-item-captcha-response">
<label for="edit-captcha-response" class="usa-label form-required">
What code is in the image?
<span class="usa-label--required"> <span class="usa-sr-only">Required</span>*</span></label>
<input autocomplete="off" data-drupal-selector="edit-captcha-response" aria-describedby="edit-captcha-response--description" type="text" id="edit-captcha-response" name="captcha_response" value="" size="15" maxlength="128" class="form-text required usa-input" required="required" aria-required="true" />
<div id="edit-captcha-response--description" class="description help-block">
Enter the characters shown in the image.
</div>
</div>
</div>
<div class="captcha__description description">This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.</div>
</fieldset>
<div data-drupal-selector="edit-actions" class="form-actions js-form-wrapper form-wrapper" id="edit-actions--2"><input data-drupal-selector="edit-submit" type="submit" id="edit-submit" name="op" value="Save" class="button button--primary js-form-submit form-submit usa-button" /></div>
<div class="comments__disclaimer padding-top-2">
<em>Please be respectful when posting comments. We will post all comments without editing as long as they are appropriate for a public, family friendly website, are on topic and do not contain profanity, personal attacks, misleading or false information/accusations or promote specific commercial products, services or organizations. Comments that violate our comment policy or include links to non-government organizations/web pages will not be posted.</em>
</div>
</form>
</section>
</div>
</div>
<aside class="nist-page__region nist-page__region--sidebar-second tablet-lg:grid-col-4">
<div>
<div
class="nist-block"
>
<div>
<div about="/blogs/taking-measure">
<div
class="nist-block no-print"
>
<h2
class="nist-block__title"
>Our Science in Your Inbox</h2>
<div class="text-long"><p>Subscribe to our weekly emails.</p>
<form action="https://public.govdelivery.com/accounts/USNIST/subscribers/qualify" accept-charset="UTF-8" method="post">
<input name="utf8" type="hidden" value="&#x2713;">
<input type="hidden" name="authenticity_token" value="GleKn0r3EFkuIRsIWsyLN6Mrqim4qc3U7eIUCWGqBFz2ziQ/qv0gnQTJUhVbKHMSlmrsC7UHIm6S8IfK6qk9EQ==">
<input type="hidden" name="topic_id" id="topic_id" value="USNIST_309">
<div class="grid-row grid-gap-1">
<div class="tablet:grid-col-8">
<label class="usa-sr-only" for="email">Enter Email Address</label>
<input class="usa-input" type="text" name="email" id="email" title="email" placeholder="Your Email Address">
</div>
<div class="tablet:grid-col-4">
<input type="submit" name="commit" value="Sign Up" class="usa-button margin-top-1">
</div>
</div>
</form>
</div>
</div>
<div
class="views-exposed-form usa-form filters nist-block" novalidate="novalidate" data-drupal-selector="views-exposed-form-search-blog-taking-measure-search-page"
>
<h2
class="nist-block__title"
>Search</h2>
<form action="/blogs/taking-measure/search" method="get" id="views-exposed-form-search-blog-taking-measure-search-page" accept-charset="UTF-8" class="usa-form">
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-k js-form-item-k form-no-label">
<input placeholder="Search this blog" data-drupal-selector="edit-k" type="text" id="edit-k" name="k" value="" size="30" maxlength="128" class="form-text usa-input" />
<div id="edit-k--description" class="description help-block">
Put exact phrase in quotes (e.g., "artificial intelligence")
</div>
</div>
<div class="grid-col-12 form-actions js-form-wrapper form-wrapper" data-drupal-selector="edit-actions" id="edit-actions"><input data-drupal-selector="edit-submit-search-blog" type="submit" id="edit-submit-search-blog" value="Search" class="button js-form-submit form-submit usa-button" /></div>
</form>
</div>
<div
class="nist-block no-print"
>
<h2
class="nist-block__title"
>Stay connected</h2>
<div><a href="https://www.facebook.com/nist" class="nist-social nist-social--facebook" title="Facebook" ><span>Facebook</span></a><a href="https://www.linkedin.com/company/nist" class="nist-social nist-social--linkedin" title="LinkedIn" ><span>LinkedIn</span></a><a href="https://www.x.com/nist" class="nist-social nist-social--x" title="X (Twitter)" ><span>X (Twitter)</span></a><a href="https://www.youtube.com/nist" class="nist-social nist-social--youtube" title="Youtube" ><span>Youtube</span></a><a href="https://www.instagram.com/nist/" class="nist-social nist-social--instagram" title="Instagram" ><span>Instagram</span></a><a href="https://public.govdelivery.com/accounts/USNIST/subscriber/new?topic_id=USNIST_309" class="nist-social nist-social--envelope" title="GovDelivery" ><span>GovDelivery</span></a></div>
</div>
<div
class="views-element-container nist-block"
>
<h2
class="nist-block__title"
>Categories</h2>
<div><div class="js-view-dom-id-0008a5de9e5830d778d5d279e8cdd68e768564a5165d8749f7eb030d554dcb6b">
<div>
<select class="usa-select ViewsJumpMenu js-viewsJumpMenu" title="-- Choose --" id="blog-categories-takingm-jump-menu">
<option>-- Choose --</option>
<option data-url="/blogs/taking-measure/categories/249466">Advanced communications</option>
<option data-url="/blogs/taking-measure/categories/248321">Bioscience</option>
<option data-url="/blogs/taking-measure/categories/248371">Buildings and Construction</option>
<option data-url="/blogs/taking-measure/categories/248416">Chemistry</option>
<option data-url="/blogs/taking-measure/categories/248486">Electronics</option>
<option data-url="/blogs/taking-measure/categories/248531">Energy</option>
<option data-url="/blogs/taking-measure/categories/248561">Environment</option>
<option data-url="/blogs/taking-measure/categories/248586">Fire</option>
<option data-url="/blogs/taking-measure/categories/248616">Forensic Science</option>
<option data-url="/blogs/taking-measure/categories/248651">Health</option>
<option data-url="/blogs/taking-measure/categories/249421">Information technology</option>
<option data-url="/blogs/taking-measure/categories/2748236">Infrastructure</option>
<option data-url="/blogs/taking-measure/categories/248866">Manufacturing</option>
<option data-url="/blogs/taking-measure/categories/248946">Materials</option>
<option data-url="/blogs/taking-measure/categories/249011">Mathematics and statistics</option>
<option data-url="/blogs/taking-measure/categories/249051">Metrology</option>
<option data-url="/blogs/taking-measure/categories/249126">Nanotechnology</option>
<option data-url="/blogs/taking-measure/categories/249451">Neutron research</option>
<option data-url="/blogs/taking-measure/categories/249426">Performance excellence</option>
<option data-url="/blogs/taking-measure/categories/249241">Physics</option>
<option data-url="/blogs/taking-measure/categories/249461">Public safety</option>
<option data-url="/blogs/taking-measure/categories/249456">Resilience</option>
<option data-url="/blogs/taking-measure/categories/249341">Standards</option>
<option data-url="/blogs/taking-measure/categories/2813456">Technology transfer</option>
<option data-url="/blogs/taking-measure/categories/249396">Transportation</option>
</select>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</aside>
</div>
</div>
<div class="grid-container">
</div>
</section>
</div>
<div data-elastic-exclude>
<!-- nist-index-ignore-start -->
<footer class="nist-footer padding-bottom-4">
<div class="grid-container nist-footer__info">
<div class="grid-row">
<div class="tablet:grid-col-6">
<div class="nist-footer__logo">
<a href="/" title="National Institute of Standards and Technology" rel="home">
<img class="nist-footer__logo-img" src="/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px" />
</a>
</div>
<div class="nist-footer__contact">
<h3 class="nist-footer__contact-heading">HEADQUARTERS</h3>
<address>
100 Bureau Drive<br>
Gaithersburg, MD 20899<br>
<a href="tel:301-975-2000">301-975-2000</a>
</address>
<p>
<a href="mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://www.nist.gov/visit">Our Other Offices</a>
</p>
</div>
</div>
<div class="tablet:grid-col-6">
<div class="nist-footer__social-links">
<a class="nist-social nist-social--x-white" href=" https://x.com/NIST">
<span>X.com</span>
</a>
<a class="nist-social nist-social--facebook-white" href=" https://www.facebook.com/NIST">
<span>Facebook</span>
</a>
<a class="nist-social nist-social--linkedin-white" href=" https://www.linkedin.com/company/nist">
<span>LinkedIn</span>
</a>
<a class="nist-social nist-social--instagram-white" href=" https://www.instagram.com/nist/">
<span>Instagram</span>
</a>
<a class="nist-social nist-social--youtube-white" href=" https://www.youtube.com/NIST">
<span>YouTube</span>
</a>
<a class="nist-social nist-social--giphy-white" href=" https://giphy.com/nist">
<span>Giphy</span>
</a>
<a class="nist-social nist-social--rss-white" href=" https://www.nist.gov/news-events/nist-rss-feeds">
<span>RSS Feed</span>
</a>
<a class="nist-social nist-social--envelope-white" href=" https://public.govdelivery.com/accounts/USNIST/subscriber/new">
<span>Mailing List</span>
</a>
</div>
<div class="nist-footer__feedback">
How are we doing? <a class="usa-button" rel="nofollow" href="/form/nist-gov-feedback?destination=/blogs/taking-measure/eye-beholder-how-lighting-affects-our-color-perception" title="Provide feedback">Feedback</a>
</div>
</div>
</div>
</div>
<div class="grid-container">
<div class="nist-footer__nav" role="navigation">
<ul>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/privacy-policy">Site Privacy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/oism/accessibility">Accessibility</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/privacy">Privacy Program</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/oism/copyrights">Copyrights</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/office-director/freedom-information-act">FOIA</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/environmental-policy-statement">Environmental Policy</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://www.commerce.gov/">Commerce.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="http://www.science.gov/">Science.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="http://www.usa.gov/">USA.gov</a>
</li>
<li class="nist-footer__menu-item">
<a href="https://vote.gov/">Vote.gov</a>
</li>
</ul>
</div>
</div>
</footer>
<!-- nist-index-ignore-end -->
</div>
</div>
<script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","pathPrefix":"","currentPath":"node\/1814551","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_speed":1200,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":".ck-editor, .nist-video-thumbnail__lightbox-trigger, a.nist-icon--mail-blue","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"after","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"viewsJumpMenu":{"blog-categories-takingm-jump-menu":{"new_window":false}},"ajaxTrustedUrl":{"\/blogs\/taking-measure\/search":true,"\/comment\/reply\/node\/1814551\/comment_node_blog":true},"user":{"uid":0,"permissionsHash":"bd6a443844dbe99b4e6942f3b1397526e760137efd2b1ee6b2d588fc414dff20"},"antibot":{"forms":{"comment-form":{"id":"comment-form","key":"8s3HerPNUiBWAup-NU0eICdfN5XSJ1VRGAW7gyEytXD"}}}}</script>
<script src="/sites/default/files/js/js_jDaFaXhHm6gPUKstNYX9eIyoQXghVs3g7rbR0QoqpYY.js?scope=footer&amp;delta=0&amp;language=en&amp;theme=nist_www&amp;include=eJxdjw2OAyEIhS_klCMRHBlLqzJRpu7efp2fppsmJvg9eI_gaX6i6Xgr-M8fH81F1ZgYqVD6NZkbfAuuSDNcZGhBe0lKAa2OECkRIp3tJsaS16ovhm9h33JodufMY68mTxWzBgjSyI_gJOV5zEBM6ilNlwXuTIHrG7H3_m-Cf2w3QqjbSul24WnMFIssMruXcG_42PKKmcsGB087Tzs7KiZeDa56W7RmN641ru_gk_4AudN_yQ"></script>
<script src="https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script>
<script src="/sites/default/files/js/js_yFXzHK1gkl-H3tLPLdnBw5DymsKPJCwJskyq7yQVS6A.js?scope=footer&amp;delta=2&amp;language=en&amp;theme=nist_www&amp;include=eJxdjw2OAyEIhS_klCMRHBlLqzJRpu7efp2fppsmJvg9eI_gaX6i6Xgr-M8fH81F1ZgYqVD6NZkbfAuuSDNcZGhBe0lKAa2OECkRIp3tJsaS16ovhm9h33JodufMY68mTxWzBgjSyI_gJOV5zEBM6ilNlwXuTIHrG7H3_m-Cf2w3QqjbSul24WnMFIssMruXcG_42PKKmcsGB087Tzs7KiZeDa56W7RmN641ru_gk_4AudN_yQ"></script>
<script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFnFGRhVWVWoNVgUHaHpaWkcXWFVaBks9LFtdUGJaAEB6WQ1NEw1YVVBGHltBUFMU","queueTime":5,"applicationTime":1086,"atts":"TBtXQQMaH0k=","errorBeacon":"bam.nr-data.net","agent":""}</script></body>
</html>
Reference in a new issue View git blame Copy permalink