A dilute tortoiseshell is a coat pattern, not a breed. Blue-gray and cream patches or a fine marbled blend come from a recessive dilution gene a cat inherits from both parents, and the patchwork depends on two X chromosomes, which is why nearly all dilute torties are female. Most are domestic shorthairs or longhairs, though the coloring also turns up in Persians, British Shorthairs and Maine Coons.
Typical adults weigh 6 to 14 pounds and live 12 to 18 years, so adopting one is a long commitment. In Nashville, that means planning for hot summers and tornado season, plus a coat routine if the cat is longhaired. Despite the folklore of tortitude, torties run from shy to outgoing, so spend time with the cat before deciding.