Dolphins body shape is sleek but their colour can vary considerably. Some, such as the killer whale, are black and white. Other dolphins like false killer whales or the pilor, are very nearly solid black. The bottlenose dolphin is usually shades of gray and darker on its back than its underside. This kind of colouring may help camouflage dolphins in the water. Looking down on them, the dark colors blend in with the ocean. Looking up from underneath, the patches of light and dark skin blend in with the sunlight coming down through the water.

Dolphins are warm-blooded and their internal temperature is about 98 degrees. They need to conserve their body heat in cold water. Like most whales the dolphin’s body is surrounded by a thick layer of fat (called blubber) just under the skin and this helps them keep warm.