[MsMarvelDuckie]

Klingons have never all been one color, though, and it's never even mentioned as a thing. They've had more controversy over the appearance and disappearance of their head ridges than of their skin colors! Even Vulcans are not all one skin color. (Spock vs Tuvok as examples, and there was a darker skinned Vulcan on either Voyager or TNG as a minor crewman.) But somehow we humans having different races is a big deal. The others are never even identified by skin color. Except Andorians, they had a blue and a pink race distinction, and apparently had some racism involved there.