A dilute tortoiseshell isn't a breed but a coat: blue-gray and cream patches or a fine marbled blend, a softer take on the classic black-and-orange tortie. The pastel shades come from a recessive dilution gene a cat inherits from both parents, and the patchwork depends on the X chromosome, which is why nearly all dilute torties are female.
Most dilute torties looking for homes are domestic shorthairs or longhairs, though the coloring also shows up in Persians, British Shorthairs and Maine Coons. Folklore about "tortitude" has little evidence behind it, so a cat's age, history and behavior say far more than color. Shedding is moderate, longer coats need regular brushing, and lifespans of 12 to 18 years make adoption a long commitment.