This is, perhaps, one of the things people are not quite ready for.
The Pharaohs in Egypt were of much more fare skin than their working class counterparts. The greek tribes, germanic tribes, slavic tribes… All of them pretty dang white.
Suppose aliens came to the planet and had a massive disagreement about how to treat their genetically engineered labor force. Or perhaps one of the factions got a little carried away and tried to make the apes a little too much like our alien overlords, and a falling out occurred.
Not really a unique idea, and one media is exploring more… But it's one thing to propose the concept in media. It's another to actually state it as fact (assuming it is fact). I can only imagine the reaction… "Blacks are descended from those who were engineered slave labor and whites were the attempt to make northern dwelling apes into more physically advanced versions of the aliens."
That would go over well.
It's all fun and games until pride starts to get kicked in the balls.
Or maybe it was the other way around. Or not at all - I am just insane.