Most smartphone users understand that one of the things that will consume your battery the fastest is having your screen brightness set to maximum. Google recently talked with developers at its Android Dev Summit about what they can do to build apps that are as easy on the battery inside Android devices as possible. The details Google offered up show that not only does battery consumption in apps depend on screen brightness, but the colors the devs choose for the apps can have a significant impact on battery life as well.
If the apps run the screen at full brightness, power consumption goes up significantly; in fact, Google notes that brightness affects power usage in a mostly linear fashion. Google's information on screen brightness used an original Google Pixel smartphone and compared power consumed in some instances to an iPhone 7; the Pixel uses an AMOLED screen while the iPhone 7 used a regular LCD. What Google found in testing was that while the Pixel consumed more power in max bright normal mode at 250 mA than the iPhone 7 on same settings consuming 230 mAh, in max bright night mode the Pixel was significantly more power efficient at 92 mA than the iPhone 7 at 230 mA.
One of the more interesting facts that Google touted at the conference was that the color value on the screen has a significant impact on power usage; at full brightness red consumes 600mW, green consumes 580mW, and blue consumes the most power at 800mW of power draw. The color that consumes the least power at max brightness levels on the Pixel is black at somewhere around 70 mA, while the color with the highest power draw is white at over 300 mA.
Google admits its mistake in asking developers in Material Design to use mostly white for their apps, which greatly cranks up the power consumption. Google touts Dark Mode and will continue to release that mode for its apps in the future as it can significantly reduce the amount of power consumed by all apps. It's not clear why Google used the original Pixel in its research rather than the new Google Pixel 3 and Pixel 3 XL. Presumably, the research was conducted when the new device wasn't available. Pixel 3 or Pixel 3 XL shoppers can buy the phone at Best Buy right now and get a free Nest Cam.