Tortoiseshell Cat Color

"Tortoiseshell" is typically reserved for particolored cats with relatively small or no white markings. Those that are largely white with tortoiseshell patches are described as tricolor, tortoiseshell-and-white (in the United Kingdom), or calico (in Canada and the United States).

Tortoiseshell cats have particolored coats with patches of various shades of red and black, and sometimes white. The size of the patches can vary from a fine speckled pattern to large areas of color. Typically, the more white a cat has, the more solid the patches of color. Dilution genes may modify the coloring, lightening the fur to a mix of cream and blue, lilac or fawn; and the markings on tortoiseshell cats are usually asymmetrical.

Male tortoiseshells are rare and are usually sterile.

• https://en.wikipedia.org/wiki/Tortoiseshell_cat