In Assassins Creed Origins, Egyptians are black and Greeks are white.

Then Assassins Creed Odyssey comes out set in Greece and suddenly the Greeks who we saw in the last game have gotten their skin color darkened by several factors because they're the protagonists this time.

When they were evil oppressors you were killing, they were all pasty white.

But now, we want a Greek locale so time to darken their skin to a more middle eastern brownish color.