Siamese cats have a unique color scheme -- white or cream colored bodies with dark feet, tailtips, and ears (points). There is a reason for this.

Siamese have dark fur.

But Siamese cats have a gene that causes selective albinism on the parts of their bodies with higher temperatures. The upshot is, the colder the body part, the darker the fur. This single mutation essentially gives these kitties their own personal softlink gradient.