Here's what you need to know:
* Most dolphins are gray. This can range from light gray to very dark gray, almost black.
* Some species are more colorful. For example, the spotted dolphin has a distinctive pattern of black spots on a white or light gray background. The pink river dolphin gets its name from its reddish-pink hue.
* Skin color can also change with age. Young dolphins are often lighter in color than adults.
* Dolphins can also have lighter bellies. This helps with camouflage, making them harder to see from below.
So, there's no simple answer to "what color is a dolphin's skin?" It's more about a range of shades and patterns!