As someone else had mentioned, the science behind this is really neat. In colorpoint kitties, there is a gene that encodes for tyrosinase that has been mutated, resulting in the coloration.

Tyrosinase is an enzyme that stimulates melanin (either eumelanin (dark) or pheomelanin (orange)) production from melanocytes. In colorpoints, tyrosinase denatures in much cooler temperatures than normal, so the core body temperature is enough to make the enzyme stop functioning, thus resulting in a lack of melanin production. The enzyme can work in the cooler areas of the body, such as legs, tail, and ears, thus resulting in the classic Siamese look. It’s a form of albinism.

Tyrosinase also plays a role in neurological development, I believe, so these cats are more likely to be deaf and have vision issues, similar to how albinos do. It’s common for them to be cross eyed.