
it's an old thing that doesn't really has to do with black people
the reason is that in the old days
if your skin was light it meant that you were wealthy enough and that you didn't work in the field
if you were tan youwere a poor country bumpkin.
so they consider girls with light skin to be more atractive (it's just rooted in their culture)
there aren't many black people asia so they are not used to it, sometimes they'll do /say offensive things without malicious intentions (i'm not saying that there's no racism ther are racists everywhere but sometimes it's from not knowing better)
then the dark fondation is a trend unrelated to black people it's a style calles kuro guaru (black gal) that goes against the beauty standards set in japan of the perfect woman (yamato nadeshi-ko) that says that perl white skin, red lips and pure/quiet personality makes you a valid quandidate for marriage.
gyaru style aim is to be/represent strong and independant females and the kuro gyarus takes it further by going against the nadeshiko look.
it's not black or white but here it wasn't made to be rude

Man, I knew about this whole 'not many black ppl in Asia, and manya Asians(mainly North Eastern) might say rascist stuff w/o malice (also it doesn't mean that there is no racism, there is)' thing.
BUT, now I actually have an idea about the gyaru fashion, Thanks!(。・ω・。)ノ♡ Your whole post is pretty informational

A more apt term is probably colorist. Different cultures have colorism for different reasons. But yes, paler skin is generally more accepted in Asia.
As far as racism goes, they mostly get it from western media. Which doesn't say much about western media. But basically they believe the stereotypes because they aren't exposed to other groups that often. And there is a range as you can imagine. Assuming a tall black man is a basketball player is one thing. Assuming he is a criminal is a step too far, regardless of the lack of contact.
I really didnt like the end of the last chapter. "YOUR PITCH BLACK!!!"
( ̄___ ̄)