I had to look them up as I did not recognize the name. This is a relatively new franchise. So the name is no doubt PC (being Canada).
Now,on the other hand, after 60 years in the CFL, the Inuit are suddenly unhappy with the Eskimos name.
My theory is that Red Blacks is an homage to the RCMP, the classic Mountie with the red tunic and black jodhpurs.
I tried out my theory on a recent fishing trip to Saskatchewan and the natives were underwhelmed