- Eumelanin produces black and brown colors.

- Pheomelanin produces red and yellow colors.

White dogs have a genetic mutation that prevents them from producing eumelanin and pheomelanin. This means that they have no color pigment in their fur, and their fur appears white.

The white color of some dogs is due to a dominant gene called C. This gene prevents the production of melanin pigment in the dog's hair.

The intensity of the white color is determined by another gene called I, which has two forms: intense (I) and non-intense (i). The intense gene produces a brighter white color, while the non-intense gene produces a creamier white color.

In addition to the C and I genes, there are other genes that can also affect the color of a dog's fur. These genes can modify the effects of the C and I genes, or they can produce entirely new colors, such as blue, fawn, and brindle.

The interaction of all of these genes produces the wide variety of coat colors that we see in dogs.