Ginger, or orange, is another allele of the fur color gene, but I made this a separate chapter since ginger works a bit differently from the other fur colors. Ginger is co-dominant to black, chocolate, and cinnamon. Co-dominance is when neither allele is dominant over the other, and both alleles are expressed, just in different areas of the animal's body. In this case, if a cat had both a black and ginger allele, both colors would be expressed on the cat's pelt in the form of patches. This is what we would normally call a tortoiseshell cat.

Here is a chart explaining each genotype, and what they mean! Of course, the allele for black fur (B) can be replaced with either chocolate (b1) or cinnamon (b2), it doesn't matter since O is co-dominant to all three alleles.

A common misconception made by a LOT of people is that ginger she-cats are very rare, which is actually not true. They're less common than ginger toms, but it is perfectly reasonable for a female cat to be ginger. In order for a tom to be ginger, their mother must have some form of ginger on them (either being a tortoiseshell, or a ginger cat. However, for a she-cat to be ginger, BOTH parents must have some form of ginger on them. This makes she-cats a bit less common, but they aren't rare in the way that male tortoiseshells are rare. Since a male cat usually has one X chromosome, male torties are EXTREMELY rare, and can only be caused by certain mutations in cats. Mutations will be explained in a later chapter!

One time, I saw this Warriors fanfiction where this person was tearing apart someone's fanfiction in the comments for being genetically inaccurate (for context, it was only about as genetically inaccurate as the Warriors books themselves). But the funny part is, this person literally said "Ginger females are super rare, so *insert character name* can't be ginger!" , and I was just laughing. I don't think it's helpful to criticize someone else's fanfiction for being genetically inaccurate, unless it has an impact on the plot in any way, or the person is aiming for realism. But if you ARE going to critique someone's lack of knowledge on genetics, at least get your facts right. Furthermore, even if ginger cats WERE super rare, that doesn't make them impossible.

And one more important thing to note is that ginger cats are ALWAYS tabbies. Even if a ginger cat has the genotype for no tabby markings (I'll get to that soon), they will still appear as tabby. The closest thing you can get to a solid ginger cat is a ginger ticked tabby, which would have very faint tabby lines, but are still tabbies.

About tortoiseshells:

So we established that tortoiseshell cats are cats with patches of black/brown/cinnamon, and ginger. A calico is a tortoiseshell with white markings on it. On a regular tortoiseshell cat, the patches appear to be brindled, and a bit harder to distinguish. However, as more white spotting is added, the patches become much more distinct. Here is an image of what this looks like, and this one is from messybeast!

There is a second variant of a tortoiseshell cat known as a torbie, or tortoiseshell tabby. Torbies are cats that have a tortoiseshell pelt, as well as tabby markings on top. I will go deeper into the genetics of torbies when I cover tabby cats!