Penguins are black and white because those color patterns protect them from predators in a natural phenomenon called countershading. Penguins, like some other animals, have coats with unique colors that keep them safe from predators above and below the water while they swim. The darker black colors on penguins' backs blend in with surrounding ocean waters, protecting them from predators in the sky while white feathers along their undersides hide them from animals below the surface.
Although all penguins have countershading, patterns vary among penguin species, and may be different between males and females of the same species. Some penguins, like emperor penguins, have other colors besides plain black and white. Emperor penguins have black feathers covering the tops of their heads, backs and wings. Their chins and the upper parts of their necks have black feathers too, while their bellies are white, and long, slim patches of yellow feathers appear on the sides of their heads. King penguins have similar markings, but are distinguished by bright orange patches along the sides of their heads.
Other penguins, such as Ad?lie penguins, have subtler markings. These penguins have black heads with a circle of white feathers around their eyes. Gentoos have white patches above their eyes while crested penguins have brilliant yellow or golden tufts of feathers above their eyes. Similar variations exist among other penguin species, giving them a unique identity.