Cat’s hair is red because of the pigment pheomelanin.
Cat’s hair is red because of the pigment pheomelanin. It’s the same reason why humans have red hair, but it’s a little more complicated in cats. Humans have two copies of a gene that makes them produce more eumelanin, which is what gives us brown or black hair. Cats only have one copy of this gene, so they only produce a small amount of eumelanin and a lot more pheomelanin.
Pheomelanin is what gives cat’s their distinctive orange and ginger fur. This is especially true for cats with tabby patterns, as these patterns are created by large amounts of this pigment. The colour comes from carotenoids found in their diet, but the cat has to be able to convert these into pheomelanin.