I thought I’ve mentioned this here, but perhaps not. My observations on beauty ideals can be summed up as follows:

“Beauty is what most people are not, but the elite are always beautiful.”

I call it the “white face” hypothesis. Beauty ideals (across many different cultures!) traditionally favored pale features prior to modernity, as they were indicators of high social status (everyone else was out working in the fields all day). When the connotation of social status disappeared, tan suddenly became in. I suppose one reason for this may be the indication of enough money to spend it frivolously, but more likely it’s just a trait idealized by celebrities and televised role models.