What happens to mixed races when they go to prison?

If some is only 1/8 black like Rashida Jones and looks white do they join the axryan brotherhood or does the one-drop rule apply and disqualify them? Would they be accepted by the black gangs? What about a "hispanic" like a puero rican or someone with only a little black blood, would they join the mexicans or do they also practice the one-drop exclusion rule? What about someone thats messed up with being jumbled up with 3 or more races, would they end up being exterminated by everyone?