Black shell color from birth to adult size. The skin is black, which fades to a gray color with time and age. These massive, round tortoises are second in size only to the Galapagos tortoises. Some think that the Aldabras actually hold the record (800 pounds), but that the Galaps average slightly larger. They can handle variable amounts of humidity in captivity once grown, but babies should be kept humid to ensure proper smooth growth.