Polar bear fur is not actually white. Instead, it appears white due to the structure of the fur. Here’s why polar bears look white: 

Transparent Fur

Each hair of a polar bear's fur is actually transparent and hollow. The hollow core of the fur scatters and reflects light, making the fur appear white in most lighting conditions. This scattering of light works similarly to how snow appears white, even though individual snowflakes are clear. 

Camouflage

The appearance of white fur provides excellent camouflage against the snowy and icy environments in which polar bears live. This helps them blend into their surroundings and makes it easier for them to hunt seals and other prey. 

Black Skin

Underneath their fur, polar bears have black skin. The black skin absorbs heat from the sun, helping to keep the bear warm in its cold habitat. 

Color Variation

Depending on the season, the fur of a polar bear can appear to change color. In the summer, polar bear fur may take on a yellowish hue due to oxidation and exposure to the sun. 

Additionally, dirt and oil can accumulate in their fur, contributing to a slightly off-white or yellowish appearance. Thermal Insulation: The hollow, transparent hairs also help to trap air, providing excellent insulation against the Arctic cold. This, combined with a thick layer of fat beneath their skin, keeps polar bears warm in extremely cold temperatures.