Since the European conquest of the planet, the fairer skin preference has been projected back onto many other groups of people, but is inherently suspicious given the circumstances within which we've learned about their cultures.

It long predates that. European slave girls (and boys) were particularly prized in the caliphate when Europe was a backwater.

Historically pale skin was prized because rich women didn't work in the fields, they stayed in doors out of the sun. Tans came into fashion with air travel. Only the wealthy could fly to say the Med for their holidays Also I suppose poor slum dwellers didn't get much sun. They only got rickets due to a subsequent lack of vitimum D.