Did you accidentally turn grey scale on in accessibility settings? Did you accidentally turn on sleep mode, which will put the phone in greyscale? Check to see if a mode is on, then see if you turned on greyscale color correction in the accessibility settings.
------------------------------------------------------------- Please mark any response that helped you as your solution. -------------------------------------------------------------
Did you accidentally tap the color correction dropper in the quick panel? This is actually a sortcut for turning on color correction in accessibility settings. I don't know of any other reason your phone would go to greyscale other than a mode or color correction. Have you tried a simple rebbot or wiping the cache partition? What was happening immediately prior to this happening?
------------------------------------------------------------- Please mark any response that helped you as your solution. -------------------------------------------------------------
