Light-on-dark color scheme

File:Zork on CRT display.jpg running on a green-on-black CRT display]]

Predecessors of modern computer screens, such as cathode-ray oscillographs, oscilloscopes, etc., tended to plot graphs and introduce other content as glowing traces on a black background.

With the introduction of computer screens, originally user interfaces were formed on cathode-ray tubes (CRTs) like those used for oscillographs or oscilloscopes. The phosphor was normally a very dark color, and lit up brightly when the electron beam hit it, appearing to be white, green, blue, or amber on a black background, depending on phosphors applied on a monochrome screen. RGB screens continued to operate similarly, using all the beams set to "on" to form white.

With the advent of teletext, research was done into which primary and secondary light colors and combinations worked best for this new medium.{{Cite web|last=Petterson|first=Rune|date=March 1985|title=Use of colors in Teletext and Videotex|url=https://www.researchgate.net/publication/281936183|website=ResearchGate}} Cyan or yellow on black was typically found to be optimal from a palette of black, red, green, yellow, blue, magenta, cyan and white.

The opposite color set, a dark-on-light color scheme (light mode or light theme), was originally introduced in WYSIWYG word processors to simulate ink on paper, and became the norm.

Microsoft introduced a dark theme in the Anniversary Update of Windows 10 in 2016.{{Cite web |title=The Anniversary Update's most exciting features: Windows 10 users weigh in |url=https://www.pcworld.com/article/415733/the-anniversary-udates-most-exciting-features-windows-10-users-weigh-in.html |access-date=2023-08-07 |website=PCWorld |language=en |archive-date=July 30, 2024 |archive-url=https://web.archive.org/web/20240730012845/https://www.pcworld.com/article/415733/the-anniversary-udates-most-exciting-features-windows-10-users-weigh-in.html |url-status=live }} In 2018, Apple followed in macOS Mojave.{{Cite web |date=October 25, 2019 |title=macOS Mojave: Dark Mode, Stacks, & More |url=https://www.macrumors.com/roundup/macos-10-14/ |url-status=live |archive-url=https://web.archive.org/web/20220808141343/https://www.macrumors.com/roundup/macos-10-14/ |archive-date=2022-08-08 |access-date=2022-08-08 |website=MacRumors |language=en}} In September 2019, iOS 13 and Android 10 both introduced dark modes.{{Cite web |last=Hardwick |first=Tim |date=June 6, 2019 |title=How to Enable Dark Mode in iOS 13 |url=https://www.macrumors.com/how-to/enable-dark-mode-in-ios-13/ |url-status=live |archive-url=https://web.archive.org/web/20220808141343/https://www.macrumors.com/how-to/enable-dark-mode-in-ios-13/ |archive-date=2022-08-08 |access-date=2022-08-08 |website=MacRumors |language=en}}{{Cite web |last=Callaham |first=John |date=2019-09-03 |title=Here's how to enable the Android 10 dark theme mode |url=https://www.androidauthority.com/android-10-dark-theme-1025156/ |url-status=live |archive-url=https://web.archive.org/web/20220808141344/https://www.androidauthority.com/android-10-dark-theme-1025156/ |archive-date=2022-08-08 |access-date=2022-08-08 |website=Android Authority |language=en}} Some operating systems provide tools to change the dark mode state automatically at sundown or sunrise.{{Cite web| title = The best dark mode extensions for Google Chrome| work = Android Authority| access-date = 2024-12-03| date = 2024-09-16| url = https://www.androidauthority.com/best-dark-mode-extensions-google-chrome-3295454/}}

Firefox and Chromium have optional dark theme for all internal screens. It will also be possible for third-party developers to implement their own dark themes.{{Cite web|url=https://www.theverge.com/2019/6/3/18647199/ios-13-dark-mode-apple-features-battery-saving-release-date-wwdc-2019|title=Dark mode is coming to iOS 13|last=Porter|first=Jon|date=2019-06-03|website=The Verge|access-date=2019-06-05|archive-date=August 7, 2019|archive-url=https://web.archive.org/web/20190807053751/https://www.theverge.com/2019/6/3/18647199/ios-13-dark-mode-apple-features-battery-saving-release-date-wwdc-2019|url-status=live}} There are also a variety of browser add-ons that can re-theme web sites with dark color schemes, also aligning with system theme.{{Cite web| title = The best dark mode extensions for Google Chrome| work = Android Authority| access-date = 2024-12-03| date = 2024-09-16| url = https://www.androidauthority.com/best-dark-mode-extensions-google-chrome-3295454/}}

In 2019, a "prefers-color-scheme" option was created for front-end web developers, being a CSS property that signals a user's choice for their system to use a light or dark color theme.

In July 2024, Wikipedia's mobile website received a dark mode.{{Cite web |last=Mehta |first=Ivan |date=2024-07-12 |title=Wikipedia's mobile website finally gets a dark mode |url=https://techcrunch.com/2024/07/12/wikipedias-mobile-website-finally-gets-a-dark-mode-heres-how-to-turn-it-on/ |access-date=2024-07-13 |website=TechCrunch |language=en-US |archive-date=July 13, 2024 |archive-url=https://web.archive.org/web/20240713040329/https://techcrunch.com/2024/07/12/wikipedias-mobile-website-finally-gets-a-dark-mode-heres-how-to-turn-it-on/ |url-status=live }} The desktop website later received a dark mode as well.{{Cite web |last=Purdy |first=Kevin |date=2024-07-29 |title=Darkness reigns over Wikipedia as official dark mode comes to pass |url=https://arstechnica.com/gadgets/2024/07/wikipedia-finally-has-an-official-dark-mode-on-desktop-and-mobile/ |access-date=2024-07-29 |website=Ars Technica |language=en-us |archive-date=July 29, 2024 |archive-url=https://web.archive.org/web/20240729234627/https://arstechnica.com/gadgets/2024/07/wikipedia-finally-has-an-official-dark-mode-on-desktop-and-mobile/ |url-status=live }}

Light on dark color schemes require less energy to display on OLED displays. This positively impacts battery life and reduces energy consumption.{{Cite web |last=Gottsegen |first=Gordon |date=Nov 10, 2018 |title=Using Android's dark mode improves battery life, Google confirms |url=https://www.cnet.com/news/using-androids-dark-mode-improves-battery-life-google-confirms-p/ |url-status=live |archive-url=https://web.archive.org/web/20221227222448/https://www.cnet.com/tech/mobile/using-androids-dark-mode-improves-battery-life-google-confirms-p/ |archive-date=Dec 27, 2022 |website=CNET}}

While an OLED will consume around 40% of the power of an LCD displaying an image that is primarily black, it can use more than three times as much power to display an image with a white background, such as a document or web site.Stokes, Jon. (2009-08-11) [https://arstechnica.com/gadgets/news/2009/08/this-september-oled-no-longer-three-to-five-years-away.ars This September, OLED no longer "three to five years away"] {{webarchive|url=https://web.archive.org/web/20120125223142/http://arstechnica.com/gadgets/news/2009/08/this-september-oled-no-longer-three-to-five-years-away.ars |date=2012-01-25 }}. Arstechnica.com. Retrieved 2011-10-04. This can lead to reduced battery life and higher energy usage unless a light-on-dark color scheme is used. The long-term reduced power usage may also prolong battery life or the useful life of the display and battery.

The energy savings that can be achieved using a light-on-dark color scheme are because of how OLED screens work: in an OLED screen, each subpixel generates its own light and it only consumes power when generating light. This is in contrast to how an LCD works: in an LCD, subpixels either block or allow light from an always-on (lit) LED backlight to pass through.

"AMOLED Black" color schemes (that use pure black instead of dark gray) do not necessarily save more energy than other light-on-dark color schemes that use dark gray instead of black, as the power consumption on an AMOLED screen decreases proportionately to the average brightness of the displayed pixels. Although it is true that AMOLED black does save more energy than dark gray, the additional energy savings are often negligible; AMOLED black will only give an additional energy saving of less than 1%, for instance, over the dark gray that's used in the dark theme for Google's official Android apps.{{Cite web|url=https://www.xda-developers.com/amoled-black-vs-gray-dark-mode/|title=No, "AMOLED Black" Does NOT Save More Battery Than Dark Gray|date=June 27, 2019|last=Raga|first=Dylan|website=XDA}} In November 2018, Google confirmed that dark mode on Android saved battery life.{{Cite web|url=https://www.theverge.com/2018/11/8/18076502/google-dark-mode-android-battery-life|title=Google confirms dark mode is a huge help for battery life on Android|last=Welch|first=Chris|date=November 2, 2018|website=The Verge|access-date=January 30, 2020|archive-date=December 8, 2019|archive-url=https://web.archive.org/web/20191208015626/https://www.theverge.com/2018/11/8/18076502/google-dark-mode-android-battery-life|url-status=live}}

Some argue that a color scheme with light text on a dark background is easier to read on the screen, because the lower overall brightness causes less eyestrain. Others{{Cite web |last=Sharma |first=Adamya |date=2020-06-29 |title=Love dark mode? Here's why you may still want to avoid it |url=https://www.androidauthority.com/dark-mode-1046425/ |url-status=live |archive-url=https://web.archive.org/web/20200924091033/https://www.androidauthority.com/dark-mode-1046425/ |archive-date=Sep 24, 2020 |access-date=2020-09-12 |website=Android Authority}}{{Cite magazine|last=Clarke|first=Laurie|date=2019-07-30|title=Dark mode isn't as good for your eyes as you believe|magazine=Wired UK|url=https://www.wired.co.uk/article/dark-mode-chrome-android-ios-science|access-date=2020-09-12|issn=1357-0978|archive-date=June 22, 2023|archive-url=https://web.archive.org/web/20230622175218/https://www.wired.co.uk/article/dark-mode-chrome-android-ios-science|url-status=live}}{{cite web |last1=Budiu |first1=Raluca |date=February 2, 2020 |title=Dark Mode vs. Light Mode: Which Is Better? |url=https://www.nngroup.com/articles/dark-mode/ |url-status=live |archive-url=https://web.archive.org/web/20230214144737/https://www.nngroup.com/articles/dark-mode/ |archive-date=Feb 14, 2023 |website=Nielsen Norman Group}} argue to the contrary. Some pages on the web are designed for white backgrounds; Image assets (GIF, PNG, SVG, WOFF, etc) can be used improperly causing visual artifacts if dark mode is forced (instead of designed for) with a plugin like Dark Reader.

There is a prefers-color-scheme media feature on CSS, to detect if the user has requested light or dark color scheme and serve the requested color scheme. It can be indicated from the user's operating system preference or a user agent.{{Cite web |title=prefers-color-scheme - CSS: Cascading Style Sheets |url=https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme |url-status=live |archive-url=https://web.archive.org/web/20210318082819/https://developer.mozilla.org/en-US/docs/Web/CSS/@media/prefers-color-scheme |archive-date=2021-03-18 |access-date=2021-03-18 |website=MDN Web Docs}}{{Cite web|last=Walsh|first=David|date=2019-01-28|title=prefers-color-scheme: CSS Media Query|url=https://davidwalsh.name/prefers-color-scheme|access-date=2021-03-18|website=David Walsh Blog|archive-date=March 17, 2021|archive-url=https://web.archive.org/web/20210317162842/https://davidwalsh.name/prefers-color-scheme|url-status=live}}

CSS example:

@media (prefers-color-scheme: dark) {

body {

color: #ccc;

background: #222;

}

}

JavaScript example:{{Cite web |title=Window.matchMedia() - Web APIs |url=https://developer.mozilla.org/en-US/docs/Web/API/Window/matchMedia |url-status=live |archive-url=https://web.archive.org/web/20210302135113/https://developer.mozilla.org/en-US/docs/Web/API/Window/matchMedia |archive-date=2021-03-02 |access-date=2021-03-18 |website=MDN Web Docs |quote=The Window interface's matchMedia() method returns a new MediaQueryList object that can then be used to determine if the document matches the media query string, as well as to monitor the document to detect when it matches (or stops matching) that media query}}

if (window.matchMedia('(prefers-color-scheme: dark)').matches) {

dark();

}

• AMOLED
• Blackle
• Night Shift (software)
• Night light (Windows)
• OLED
• Solarised (color scheme)

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Category:User interfaces

Category:Display technology

Category:Color schemes

Category:Computer graphics