Yes! Most sources indicate that the long, coarse guard hairs, which protect the plush thick undercoat, are hollow and transparent. The thinner hairs of the undercoat are not hollow, but they, like the guard hairs, are colorless. The hair of a polar bear looks white because the air spaces in each hair scatter light of all colors. The color white becomes visible to our eyes when an object reflects back all of the visible wavelengths of light, rather than absorbing some of the wavelengths.