So why do guys in hentai almost always have dark skin?

Manly tan.

karharoth said:
So why do guys in hentai almost always have dark skin?

Its to make the girl stand out more to the viewer. People tend to shift their view to brighter colors before they do to darker ones.

Maybe it's a black guy and not a tan,did you ever think that's why his skin is dark,and plus any time a white or chinese lady is have sex with a black guy, you always see them hold there stomch.