Shackman,
Segregation in America had much to do with bands of the same color for several decades. Hotels, restaurants etc, were part of that, not allowing blacks and whites to stay at the same hotels, or even eat at the same restaurants. The jazz idiom was and is still colorblind. Many jammed together in the afterhours, and as time passed, bands and smaller groups, used mixed races of musicians. They were looking for the best, that understood and performed as the band desired; color didn't matter.
Still happening today in jazz. All mixed and integrated, and I'm glad about it. Just looking for the best music I can find, and don't look to see what color they are, or whether they are male or female. Some of my current favorite artists are female, and they kick butt, too. tp