Yeah, that wasn't a good example since taste is weird. A better example would be that most people would agree that the pink background on this sprite sheet is almost painful to look at while other, more luminous, elements are fine. If our perception significantly varies, then simple mid-luminance color blocks shouldn't have consistent effects from person to person. Parts of that yellow gradient on the right should cause more strain to someone you know than the magic pink field if perception is strongly variable.