Go to video equliser and then change saturation back to 4 or 5, i just figured it out myself and i had the same problem, i must have pressed a hotkey for saturation by accident
I just had the same problem and i figured it out, i must have pressed a hotkey button, as i checked my equaliser settings in video > Equaliser, and the saturation was on 0 so changing it back to 4 or 5 should fix it