Question

which screen mode support only black and white colours​

Answer 1

Answer:

Dark mode , I guess...

Answer 2

Wind Down mode is designed to help reduce eye strain before sleeping and to prevent your sleep from being disturbed. When Wind Down mode is enabled, the screen on your phone will appear to be in black and white and will continue to do so until the mode is turned off.

Go to your phone's Settings, then go to Power Saving Mode. Under the power saving mode tab, toggle off the power saving mode. This will change the screen color from black and white back to color. Another solution you can try to change screen color from black and white to color is to turn off the Reader mode.

HOPE THIS HELPS !!!