Dude lets not be silly I wholeheartedly doubt that black people are afraid of a mulatto uprising I think black people are more afraid if not most afraid of not progressing due to perceived racism real or not by whites who have the real power Besides there have been plenty of mulatto those people who phenotypically have kind of a beige skin color and caucasian features uprisings against darker skinned people be they in North Africa or Western USA or South America Actually these people whether they be mestizos mulattos dark caucasians are already racist towards darker skinned people which most of the time includes Black people and native Indians  ie the systemic racism is already there There isnt going to be some sort of big bang uprising wherein mulattos start to uprise against darker skinned people or black people  The concept of black and mulatto arent diametrically oppossed like the concepts of black and white The worst thing that can happen is balkanization  Furthermore as white people continue to identify as white I dont see the idea of blackness going anywhere soon