Albino on all animal species, is a cover-up gene. When an animal has 2 copies of the c Albino gene (c/c) they turn pure white, but are still genetically whatever color they originally were, underneith the white. So a black rat, who has the albino gene, would still be genetically black, but you would only see the white with pink eyes. :)
Albino is probably the strongest gene I can think of, lol. It covers up all colors and interacts with none as far as I am aware (at least in rodents.)