OLED display panels can display black pixels with almost no energy cost. So it follows that the use of apps with more black would save your phone battery. Google approves, and it designs several of its Android apps with a dark theme.
The company said so much at its Android Developer Summit in Mountain View yesterday and dramatically shows energy saving when using Dark Mode in its official apps on an OLED screen. At 50% brightness, the new Dark Mode interface in the YouTube app saves just under 1
You can see the technical breakdown from the Developer Conference in the video below.
Battery-saving black interfaces have been known for years – that allows continuous environmental displays, first seen on Moto X and then adopted by Google, Samsung and others. This trick does not apply to LCD monitors, which are used in some budget patterns (including cheapest Android phones and iPhone XR). However, given that a large percentage of users will see a significant battery rise from darker apps, and even those who can not appreciate the rest of the eyes, Google pushes more Dark Mode options into their own apps and encourages developers to do the same.
While Google's default color scheme has used white as a base since its overall material design several years ago, it appears that the company plans to release more apps in a dark mode like YouTube and the standard Android mobile app. The latest Android OS edition, Pie, contains a system-wide dark mode option: enable it by going to Display Settings and touching "Device Theme."
Source: YouTube via Slashgear