The latest Google Play Books update brings the useful Night Light feature to Android devices. The features automatically adjusts the temperature and brightness of the screen based on the time of the day. To disable / enable night light for Google Play Books on Android devices, do as follows:
1. Open the Google Play Books app (Make sure it is updated and running the version 3.7.45 or later)
2. Open the book you are going to read
3. Tap the screen to show the quick settings on the top and then touch the A icon (an A with underline)
4. Now make sure the Night Light toggle button in enabled.
5. From now on, the Night Light will automatically adjust the screen and delivers the best experience based on the time of the day
** To get to know more about the Night Light on Google Play Books, tap the (i) icon next to the Night Light text
** To turn off Night Light, simply toggle off the button