On both sides of the Atlantic there has historically been a "light is good, dark is bad" mentality. Nonsence, of course, but so is much of social classification.
Even among an essentially homogenous people, lighter skin was historically perceived as better. Mostly because a darker skin meant more exposure to the sun, which implied manual labor, which implied serfdom. Bluebloods, after all, had very pale skin.
With the advent of more modern mores, an interesting switch took place. A darker, tanned skin became preferable because such a skin implied more leisure time, hence greater wealth. But this was true only if the untanned parts were very light in color, and located in the proper places. For example, a tanned back was good, unless you had pale legs, in which case it was very bad, because it implied you were the lowest sort of manual laborer (a shirtless navvy).