It sounds like a magic trick! A polar bear’s fur is transparent, and underneath all that "fuzz," their skin is as dark as coal.
If you look at a polar bear, you’ll see a giant, fluffy white animal. But if you could shave a polar bear (which we don't recommend!), you would find a big surprise: they are actually black!
A polar bear's fur is not white. Each hair is actually a clear, hollow tube, like a tiny straw. So why do they look white? It’s because the hollow hairs scatter and reflect light, just like snow or clouds do. When light hits their fur, it bounces around and tricks our eyes into seeing white. This helps them blend in perfectly with their icy home.
Underneath those clear hairs, polar bears have pitch-black skin. There is a very smart reason for this. In the freezing Arctic, the sun is very weak. Black color is the best at absorbing heat from the sunlight. Those clear, hollow hairs act like tiny fiber-optic cables, helping to trap the sun's warmth and send it straight down to their dark skin to keep them cozy and warm.
Since the hair is clear, it can sometimes change color based on the environment. In zoos, tiny plants called algae can grow inside the hollow hairs, making the bear look a bit green! In the wild, oil from the seals they eat can turn their fur a yellowish color.
Polar bears have transparent, hollow fur that reflects light to look white. Underneath, their skin is black to soak up as much warmth from the sun as possible. They are masters of disguise and masters of staying warm in the coldest place on Earth!