I agree with forever_pit as well. I think a lot of dogs, especially those who are raised in predominantly white areas are standoff-ish towards someone of a different color. I have seen a lot of dogs act different around people with darker skin. My dog is indifferent. The home he came from was "multicultural" ie mom was white, dad was black, kids were mixed. Most of our neighbors are colored and he acts the same around everyone. My dog may not be scary looking, but the only people who seem to show fear around him are mothers with young children who do not have dogs (which is justified, kid comes running at us and mom freaks out, I just have Hudson sit), and our neighbors from India. They will make a 15foot detour from out sidewalk to avoid Hudson. The kids are young and seem unphased but will probably learn that fear. I shouldn't call it a fear though, it is part of the culture to view dogs as dirty and not pets. Once they had a problem in their apartment and the wife came to our door asking for help and Hudson just stayed on the couch, didn't do anything and since then they have cut down the detour to about 6 feet haha.
Back to the "mothers" point though, every kid I see wants to pet Hudson. Most kids ask first, and I tell the parents they are welcomed too, but that he is a strong and excitable puppy. Won't bite but a wiggle with his hips can knock a kid over. Once someone takes a moment to talk to you, I find they are much more relaxed. Again though, my dog looks (and gives off the vibe) of very unthreatening so I guess my situation is different.