Actually, I was more thinking of human rights in general, not specific racial treatment. Amnesty International ([link|http://www.amnesty.org/|[link|http://www.amnesty.org/|http://www.amnesty.org/]] is perhaps the most vocal general human rights group and does not speak highly of Cuba's treatment of political prisoners.
But racism, specifically, a Google search reveals many pro and con stories, sometimes even within the same article, such as [link|http://64.21.33.164/CNews/y98/sep98/17e9.htm|this one] from the Dallas Morning News. Officially, there's not supposed to be racism. To say there is means you're disagreeing with the regime which means there's a good possibility of being jailed for anti-revolutionary sentiments or something like that. But it may still be as unofficially entrenched in Cuba as it has been in the U.S.