Wow, you raise some interesting points. I’m a blonde woman, married to a man with hair so dark it’s almost black, with a daughter who’s got chestnut brown hair like my mom and a son with hair like a copper penny that has darkened over the years. So many stereotypes for “blondes” and “gingers”!!
Come to think of it, same with eye color — the rarer the color, the more negative the stereotypes: “green-eyed monster” or “icy blue eyes” (cold/frigid)…
I think it’s like most things — humans are inclined to feel better about themselves if they can find some way, no matter how ridiculous, to compare themselves favorably to someone else. It’s pretty ridiculous when it’s based on immutable characteristics instead of on skill, wisdom, kindness, etc. — but I guess if that’s all you’ve got, it’s all you’ve got. ;)
White people have lots of skin tones, though, too. I, personally, identify as ruddy beige with a very light smattering of freckles. (I have to burn to tan — I’m a mix of Scandinavian pale, ruddy Scottish, and German olive — the latter only reflected in my resistance to burning in the sun, but I passed it to my daughter and my son missed it completely, poor thing!)