The November 2018 security patch forces Night Mode on when you enable Battery Saver, even when Night Mode is set to “Always off.”

We do not know if this is a bug or a new feature.

Google confirmed that black is better for your device’s battery than white if your device has an OLED display.

With the November 2018 security patch now available for Pixel, Nexus, and Essential devices, Android Police found a weird change with how Battery Saver and Night Mode interact with each other.

It was found that switching Battery Saver on now forces Night Mode to also turn on, regardless of whether you set Night Mode to always be off in developer options. You can still manually turn Night Mode off, but it will turn back on the next time you enable Battery Saver.

Android Police also noticed that turning on Battery Saver sets Night Mode to Always on, even though Night Mode was previously set to Always off. Even stranger, turning Battery Saver off reverts Night Mode back to Always off.

This means that Battery Saver now overrides Night Mode, which might be a good thing if you want to save battery. During its Android Dev Summit, Google confirmed that black puts significantly less strain on the battery than white does. This might be why Google continues to update its apps with dark modes, even though the company’s Material Design initiative uses white as the primary color.

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As such, it would make sense for Battery Saver to automatically turn Night Mode on. Then again, Android Police pointed out that Night Mode within developer options only controls the notification drop-down; it does not control the app drawer.

On a related note, it looks like the November security patch lets you turn Night Mode on based on the time of day. The setting might not be working as advertised at the time of this writing, however.