Why Does a Siamese Cat Turn Black?

Siamese cats darken because a temperature-sensitive TYR gene makes tyrosinase overactive below 30C, boosting melanin in cool areas like the face and paws. Shaving only speeds it up; warmth restores the lighter coat. Keep your cat warm to limit darkening.

The Secret of Siamese Cats

A Siamese cat's coat darkens in cool areas because its tyrosinase enzyme is temperature-sensitive, boosting melanin where skin is cool. The fur lightens again in warmth, so color shifts with season and age, a normal trait, not a health problem.