Speaking as a White person, I don't think this is "overt" racism - it is simply White people showing a preference for other White performers on the show. The partiality of viewers to vote for Whites that are not as good as other Black colleagues is obvious, and not a little embarrassing for the BEEB.
No doubt, if this competition took place in a mainly Black country and there were a few White performers in the show, the Whites would get voted out "unfairly". I don't think there is much that can be done about this sort of thing.
Mark Ramprakash is mixed race, is he not, attractive and fairly light skinned. The same can be said for Alesha Dixon. White viewers were aware that she is half White. Colin Jackson was a far better dancer than the White bloke who eventually won. Spoony was also far too good a dancer to have gone when he did. Etc., etc., etc.....
I don't vote on this show - but would have supported Don and Cherie, because they are in a similar age group to myself. Cherie is a far better dancer than Don, but in turn, he is far better than many of the people still left on the show!
I wouldn't support really bad dancers, even if I liked them - that, to me, is pointless. The colour of their skin plays no part whatsoever, in any decision I might make.