The percentage of the population that is black v white is irrelevant. What might be marginally relevant is the percentage of CPL/ATPL holders that are black. If 95% of licence holders are white, why on earth would you expect BA to have greater than 5% non-white pilots?
Anyway, this is all irrelevant tosh, who performs best is the only relevant factor. If the white guy is better than the black guy, tough, and vice versa.