A dilute tortoiseshell is a coat pattern, not a breed. The coat shows blue-gray and cream in patches or a soft marbled blend, thanks to a recessive dilution gene. Nearly all are female, because the orange gene sits on the X chromosome. Most are domestic shorthairs or longhairs, though the coloring also appears in Persians, British Shorthairs and Maine Coons.
Folklore credits torties with attitude, but coat color doesn't reliably predict personality. Expect a medium-sized cat, typically 6 to 14 pounds, with a 12 to 18 year lifespan and moderate shedding. For a Denver apartment or condo, what matters most is the cat's age, health and comfort with noise and company, and you can learn much of that by spending time with her.