Can a Siamese cat turn black and go white?

It is possible. The tyrosinase enzyme in Siamese cats is less stable, so the colour of its fur will change according to the surrounding temperature. Generally, the lower the temperature, the more pronounced the melanin gene in Siamese cats will be. When the temperature rises, the Siamese cat’s tyrosinase activity decreases, not enough melanin is synthesised and the coat will slowly go back to white.