When do Siamese cats stop changing color?

Siamese cats usually stop changing color at around one year old, though their coat can make subtle shifts for up to two years. Their color points (ears, faces, paws, and tails) darken as they mature because of the temperature-sensitive gene that controls their pigment.

The cooler the environment, the darker those points tend to get. So, even after their main color change slows down, small shifts can occur depending on the season or where they live. But by the time they’re around two years old, their color pattern is mostly set.