I see him as being more (butt)hurt from the people of Boston than racist against white people. He gave Boston 11 championships, and all the media and fans could think the whole time is how they didn't want a black man on their team, or how (according to the do entary) they thought his coach was propping Russell up because there was no way a black man could do it on his own. If he had hard feelings toward white people, it was probably reflective, like, "I don't think you think we're equal, so I am wary of you." It doesn't seem like he had any issue making friends with white people or supporting people of all ethnicities in his civil rights work.