I didn't too like the idea of a black Vulcan - but no, it has nothing to do with "terran racism", I had huge problems with the white Andorians from Enterprise (how were they called?). It's because it was different what we've seen before - I mean always humans were having different races, but Vulcans were always white (or yellow-white or what's the correct term for Spock's skin colour), Klingons were always black (even though in TOS era they were played by white guys with dark make up), Orions were always green, Bolians were always Blue, just like Andorians ...

If they originally in the 60's defined that there are different races on all (or most) planets I wouldn't have a problem with a black Vulcan (or white Andorian...). It just feels "weird". But Tim Russ is a fine actor, and he was a good Vulcan (even when he was a bit too emotional in some episodes). I hate when they change things (like the Remans who were always the same race as the Romulans and Vulcans but suddenly after Nemesis they're vampires :-(