In a more general sense, any person who sides with people of another "race" over their own can be called a "race traitor".

A black who is complacent or sides with whites is called an "Uncle Tom" after the character from the book "Uncle Tom's Cabin" (the single most poorly written book that I have ever had the displeasure of reading).

Also oreo (after the cookie that is "black on the outside, but white on the inside").

The last of the most common being "X Lover", where X can be whatever "other" group that the person is siding with.