"But as far as your study goes, it has very little to do with the rainbow (if anything at all)."
Well - duh! Like I haven't been explaining this for two days now?
"Similarwise you can argue that Northern people are more sensitive to blue shades and southern people are more sensitive to red shades (probably true to a very small degree)."
Actually, hungry people are more sensitive to blue and fed people to red.
"So if all those people want to mark black and white as a part of the spectrum, well it's just plain wrong."
I wrote a really long answer to this one, involving Chinese people with long purple wings, which this correction made unnecessary. You got the point precisely right: what interests me is what kind of people draw "weird humans", and what kind of "weird humans" they draw, e. g. "do all fiftyish black male accountants draw stick figures with five legs?"