I've been trying to find the right words for this for a month and can't, so whatever, have poorly formulated words.
In the Sims community (and others where you can easily create large numbers of your own characters, probably, but this is the one I'm most familiar with), I've noticed two interesting trends.
"A sim who looks white and doesn't have visibly non-white ancestors in their family tree* has to be white."
"All People of Color are basically white people with brown skin or ethnic hair/accessories/clothing/names."
I feel like these two are somehow related, but I can't get my arguments together. (I have not seen anyone espousing both beliefs simultaneously, though.)
*Sims made in the character creator or spawned as NPCs by the game don't come with family trees unless the player makes one.