The color of the fur is an example of "phenotype".
Step-by-step explanation:
All the measurable features of an entity arising from the relationship of complete genetic descent of the genotype with the atmosphere, is understood as phenotype. This include conduct, biochemical traits, colour, shape and size. Thus white fur in polar bear helps them to camouflage their surroundings i.e arctic climate. Basically the polar bear skin is balck color but fur covering their skin are yellow as there is no white pigment on the coat of the polar bear. Their body fat helps them to keep warm while swimming also and double layered fur insulate them.