Android - Force Android to display in grayscale
Android 5.0 Lollipop provides this feature by default:
Enable Developer mode (by tapping build number within
Settings
>About phone
multiple times)Go to
Developer Options
and turn it on.Under
Hardware accelerated rendering
you will see option calledSimulate color space
, click it and set it toMonochromacy
.
A launcher will not put the whole system in grayscale, only your home screen.
The Samsung Galaxy S5 has a true grayscale function you can enable system wide.
If you don't want to buy a Samsung Galaxy S5 then try CF.Lumen https://play.google.com/store/apps/details?id=eu.chainfire.lumen
It can color the screen to a specific tint. As a side effect the battery life will increase a lot.
If you have a Samsung phone, but not necessarily the S5 then you can use this root app to put everything into true monochrome (grayscale):
https://play.google.com/store/apps/details?id=mobi.pruss.GalacticNight