The real bitter escaped tomb vampire was played by a Hispanic actor. (I would not have known, except he used to work on a soap opera my mom watched. He also played a reporter on The Closer.) His girlfriend was black.
But other than Anna and her mother I don't recall there being much diversity amongst the vampires, but maybe that will change. (I recall the tomb's first escapee. I actually felt sorry for him when he apologized to the hiker he met and was about to chow down on.)
Most of the witches were/are related to Bonnie and the awesome Warlock. However, Gina Torres' character and the new lady just introduced may not be. They did not really give much background info the bartender played by GT other that she knew Lexi, Damon and Lexi's boyfriend and was a witch.
I don't really recall warlocks/witches that were white. They must have not made an impression. I know that the lady helping Klaus was the Warlock's daughter, and I loved the Warlock! I was sad when he and his son died.