Why does some cats have yellowish colored fur?

Svar: ”Cats can have yellowish fur due to a genetic mutation that causes an overproduction of the pigment pheomelanin, which gives a yellow or reddish color to the fur. This mutation is most commonly found in Siamese and Tonkinese cats, but can occur in other breeds as well. Some cats may also have yellow fur due to environmental factors, such as exposure to sunlight or certain chemicals.”