Some lore tie ins would be good sure.
That said I don't see how it's strictly necessary either. We're talking about something that's purely cosmetic and I'm not saying we need to represent every ethnicity as it is on earth or even use ethnicity as a measure. But showing that there's some diversity and giving the players the option to pick from that diversity, in my mind anyway, is only going to be good.
But yeah, if someone wanted to write some lore that would be great too
I'd like to play a black furred yeek. Black furred yeeks have a genetic mutation and are generally revered among their kind.
Or an albino yeek. Also a mutation. But generally shunned by other yeeks.
Or a yellow furred yeek. Fairly common genetic mutation. No social status one way or the other.
This is why I don't write lore. But you get the idea.