That could be a number of things, One-you could encounter black women who are only attracted to ethnic features. Two-you could encounter black women who aren't usually approached by white men. I could go on and on, but I think those might be two of the main reasons you aren't getting responses from black women. Personally, I fall in both categories. I am only attracted to ethnic features and could not imagine being intimate with someone who didn't have those features AND white guys never try to approach me, so if I am approached I am in a state of shock. So much so that I was approached for the first time by a white guy 2 weeks ago and just really wanted to laugh when he told me that I was beautiful. (I didn't laugh though)