This is a great picture of a black Sphynx cat and I don’t know who took it. Please come forward. The fact that hairless cats can be skin coloured, black, tortoiseshell, bicolour and patterned etc. tells us that their skin follows the coat that they would have had but for the fact that they have a mutated gene inside them which makes them hairless.
The black colouration exists because the pigment producing cells in the basal layer of the epidermis called melanocytes take on the colour of the pigment that they are producing or there is a vestigial hair strand in the follicle which has its colour and pattern dictated by the genes controlling colour inheritance. The pigment is called melanin. Melanin is responsible for different hair colour and in the case of hairless cats what looks like the colour of their skin.
Other genes affect how the melanin is deposited in the hair such as the inhibitor gene (I) and the agouti gene (A). The hairlessness of Sphynx cats is caused by a recessive gene symbolised by hr. You might know that Sphynx cats are not completely hairless. Various parts of the body are nude but some are not such as the muzzle and feet which are covered in a fine down. The hairless condition is called hypotrichosis.
Sphynx cats build up a lot of ear wax which can be mistaken for ear mites.