This is all about demographics depending on where in the U S. we're talking about. In states where there is more ethnic diversity i.e. New York, California, Florida, Texas you're more likely to find ethnically integrated gangs as depicted in the movie Colors in 1988. However, in most cases gangs are drawn from their immediate socio-economic environs and the ethnicities that populate those areas which are typically in the lower economic rungs of society so you see some diversity with Blacks and Hispanics mixing due to Black Hispanic intermediaries which occurs more in the Carribean Hispanics than in Mexican and Central Americans. That being said, this is not generally the case and most gangs are populated by those who live in the neighborhood controlled by that gang and represent the ethnicities in that area. Illinois, Tennessee, Georgia are less ethnically diverse and reflect that in the ethnicities of their gang populations.