Dilute tortoiseshell is a coat pattern, not a breed. The blue-gray and cream patches come from a recessive dilution gene, 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 appears in Persians, British Shorthairs and Maine Coons.
Expect a medium-sized house cat of about 6 to 14 pounds with moderate shedding and a lifespan of 12 to 18 years. "Tortitude" is folklore, so judge a cat by how she acts when you meet her, not by her color. Long-haired cats need regular brushing. Whether she turns out to be a lap cat or an independent explorer, affectionate and curious is the usual mix.