Help screen has gone dull no colour

[Android Question]

My screen has gone all dull there is no colour at all

 

[Hadron]

So what did you do before it happened? Has the phone been dropped, has it ever got wet, did you install an app, try tweaking some settings? Is it just the saturation that has changed, or has the brightness changed too? What type of phone is it and what software version?

 

[mikedt]

Someone gone into the developer settings and set it to monochrome? By accident? Maybe as a prank?