Google Play Books 5.4 adds a dark theme in the main UI
It seems like every other day another Google app gets a dark theme. Just to recap the latest additions, the Play Store’s dark theme is rolling out for real this time, Google Fi has a dark theme, Files by Google has a dark theme, etc. Google Play Books is the most recent app to gain a dark theme and support for Android 10’s system-wide setting.
If you’ve used Google Play Books before you may be thinking it always had a dark theme. The app has always allowed you to use a dark background with white text while reading books, but the actual main UI of the app was a standard light theme. The dark theme finally makes the main UI dark and will automatically change the reading view to dark as well (though you can still customize it to your liking).
Google Play Book’s dark theme appears to be a server-side switch. I updated the app to the latest version, 5.4, which can be download here, but I still don’t have the dark theme. I also may not be fully rolled out yet as there is no toggle for the theme in the settings. Either way, it should be available soon. This solves a pretty annoying problem that anyone who reads a lot of books will understand. There’s nothing worse than reading a book in dark mode and then being blinded by the white main menu.
Source: Android Police