This is literally just more excuses. There were black nobility in Europe. Unfortunately, you’ve exposed your racism. In fantasy, you don’t have to explain why an elves ears are pointy. Skin is just an organ. There’s no need to explain why someone has a darker organ on their body than another person and especially not in fantasy.

There are rules to fantasy but focusing on explaining melanin distribution is not one of the them. Sorry try again.

I would be shocked if you even knew what the underpinning traditions of fantasy are.