Calico and Tortoiseshell cats do not belong to a specific cat breed, but are differentiated due to their peculiar color pattern. There are several cat breeds with the specific color pattern, as of Calico and Tortoiseshell cats. For a cat to be categorized under Calico cats, it should have three primary colors – white, black and orange. In case of Calico cats, the coat color is brindled with patches of red color and black or chocolate color. Hence, the only difference between Calico and Tortoiseshell cats is that in the latter case, there is little or no white patches. The genetic factor, responsible for their coloration is the same.