The extinct woolly mammoth, Mammuthus primigenius, probably had both dark and light coats, according to a team who have analysed variants of the Mc1r gene in a 43 000 year old bone from Siberia. Their article is in this weeks Science, abstract here.
How cool is that? The mammoth even has an NCBI taxonomy entry, linking to 131 nucleotide sequences, 76 protein sequences and a genome project. I find sequence data from extinct organisms endlessly fascinating – there are also 8 records (1 protein, 7 nucleotide) for Neanderthals.