Android 7.0 was said to come with a feature called Night Mode and this means that owners can change the blue light of their display to an amber one. This is said to help people to fall asleep faster as the blue light has a negative impact on the sleep cycle.
The Android 7.0 developer preview had the Night Mode but when it was launched for the public this mode was hidden. The mode is shown on both the Google Pixel and Pixel XL as the devices offer Android 7.1 and the drivers that are needed to run it.
However other handsets which have Android Nougat 7.1 don’t offer the Night Mode, which means that up to now it has been exclusive to the Pixel handsets. Now it is looking as though the new HTC U Ultra is going to offer up the night more out of the box.
If you scroll down on the notification bar and the click the screen icon the display will turn to amber.
You can also get the same effect on the HTC U Ultra by customising the Nigh Mode to turn on and off at certain times. To do this go into settings and Display – Gestures and Buttons – Night mode.