What color/colour is a polar bear's skin?

Black is correct: beneath a polar bear’s seemingly white coat, its skin is jet black. Black surfaces absorb more of the sun’s energy, helping the bear retain heat in the Arctic. The “white” appearance comes from the fur, whose translucent, often hollow hairs scatter light, making the bear look snowy while trapping warm air over thick blubber. Memory tip: think of a polar bear as solar-powered—black skin as the panel, clear fur as the cover. Fun fact: in some zoos, polar bears have appeared green when algae grew inside their hollow hairs, a reminder that the fur isn’t actually pigmented white.