English: Comparison of plumage color in full sib chickens differing for their genotype at the C locus (Thyrosinase-Gen). On the left, a chicken carrying the wild type allele at the C locus exhibits a colored plumage as determined by other feather color loci. Here the animal carries the wild type allele at the Extension locus, the wild type allele at the Columbian locus and the silver allele at the Silver locus. On the right, a recessive white chicken, full sib from the previous one, exhibits full white plumage.