It's something that most Samsung users have been aware of since the Galaxy S2 launched; AMOLED (OLED) displays use much less power when showing dark or true black wallpapers. In its quest to implement its Material Design that brought blinding white brightness to its apps as well as encouraging app developers to follow suit, Google has only now realized that using white backgrounds on an OLED panel does no favors to the phone's battery life.
During its Android Dev Summit, Google acknowledged that the widespread use of white throughout its apps and the Android system wasn't exactly battery-friendly. Indeed, OLED panel's pixels use the most energy when displaying white, and the least when showing a dark or black color. With Samsung planning on adding a system-wide night mode that will do wonders for battery life of Galaxy handsets with its new One UI, it would seem that a dark theme has finally become a priority for Google.
You can see just how much less power dark mode uses as opposed to the normal manner with the display set at 50 and 100% brightness above. We aren't just talking about a couple of percentage points here, this is a 14% saving when the display is at 50% brightness, and a whopping 60% at full brightness.
Despite being late to the dark mode party, Google has added the feature to apps such as YouTube and Messages recently, and hopefully, we'll see a proper true black or dark theme implemented across the Android platform in the months ahead.
Source: SlashGear
How to enable Dark Mode in the Android Messages app and on the web
Dark Mode finally comes to YouTube TV’s web app, and this is how you enable it
Pixel Launcher set to get dark theme toggle in future Android build
I always preferred ics Holo style. I thought material design was harsh & bad for your eyes.