The color range in a litter is determined by genes inherited from the parents, and whether those genes are dominant or recessive.
Each kitten will inherit genes from both parents, but in a unique combinations.
Genes are found in pairs. Black is dominant to chocolate and cinnamon, so a cat with one balck gene will be black, whereas if it has no black genes it will be chocolate or cinnamon. Within this same pair, chocolate is dominant to cinnamon, so a cinnamon cat must have two cinnamon genes (a cat with one gene for chocolate and one for cinnamon will be chocolate in color). The dilute gene, which dilutes the pigment of a cat from black to blue, chocolate to lilax, cinna,on to fawn, or red to cream, is recessive. In order for a cat to be a dilute color it must have two dilute genes.
A tabby pattern is carried by the agouti gene which gives each hair a dark tip and alternate bands of light and dark color. A non agouti gene blocks the production of the light band in each hair, so producing a solid colored coat. White fur is the product of a gene which carries no pigmentation at all.
Cat Color Mutations
Black – The first color recessive mutation from the ancestral grey/brown agouti. Produces an extremely dark, solid color perceived as black.
Chocolate – Recessive gene to black creating a dark brown.
Cinnamon – Recessive gene to black and chocolate. Carried on the same gene locus as chocolate, producing a light brown color with a warm (almost red tinted) tone.
Orange – Sex linked gene (carried on the X chromosome, so females XX can have two such genes, males XY can have only one). This alters black, chocolate and cinnamon to an orange (red, auburn, ginger) color. Females are not sterile.
Dilution – Very often known as the blue gene as the presence of the recessive dilution with black creates a grey (lavender blue) individual. Alters the structure of the pigment cells. Dilution + black – blue. Dilution + chocolate = lilac. Dilution + cinnamon – fawn. Dilution + orange = cream.
Tortoiseshell – The presence of the orange gene plus black and its recessive colors of chocolate and cinnamon creates the two colores tortoiseshell female i.e. black, chocolate and cinnamon tortoiseshells. In combination with the dilution gene the pastel blue cream, lilac cream and fawn cream are created. The rare occurence of the tortoiseshell male is probably due to the presence of an extra X chromosome. The males are usually sterile.
Inhibitor – Dominant and, as its name suggests, inhibiting, this gene reduces ground color, e.g. the rufous color of the brown tabby to the pewter ground of the silver tabby, or converting a self cat to a smoke.
Dilute Modifier – Dominant gene, the presence of which is still disputed. Creates a rather dull brownish grey color known as caramel. It has no effect on the dominant colors black, chocolate, cinnamon or red. Probably originated in Chinchilla Persian stock and is to be found in several breeds of pedigreed cat.
Full color and its recessives – Recessives to full color are Burmese, Siamese, and blue eyed and pink eyes Albinos. Burmese affects black, reducing it to a lustrous brown, or sable. In the siamese cat, black becomes a warm toned seal. Albinos are almost completely lacking in pigmentation (the blue eyed version) or entirely without pigmentation (the pink eyed version). Both may be completely or incompletely light sensitive. Extremely rare in cats, although a race of Albino Siamese was discovered in America.
Cat Pettern Mutations
Agouti – The dominant ancestral pattern of the domestic cat in which the individual hairs of the coat are banded with color. Normally light or grey at the roots of the hair with the darkest color at the tip
Tabby – A range of pattern genes which is not seen unless in conjunction with the agouti gene or the orange gene. The mackarel tabby has thinly striped markings like those along the sides of the mackarel fish. The spotted tabby, in which the thin lines are broken down into clearly defined spots, may be a recessive to the mackarel tabby or created as the result of the effects of polygenes. Abyssinian or ticked tabby markings are reduced almost entirely or restricted to face, legs and tail. This is the dominant pattern. Blotched, marble or classic tabby markings include a bulls eye on each flank and further marbling of color on an agouti based ground color. The gene causing this is recesive to the other forms of tabby marking.
Tipping or shading – It seems likely that the fairly recently discovered wide band gene combined with the agouti gene, affects the degree of color shows towards the tip of each hair. The effect of the gene varies from the lightest of tipping, as seen in the chinchilla, to quite heavy shading, where as much as mayy be mimicked by a very heavily silvered smoke, although never to the lightness seen in the chinchilla. The presence of the wide band gene appears to be confirmed by the existence of the golden chinchilla or shaded cat, which is rufous with dark tips to the hair. The ground color has not been inhibited.
White – Dominant gene which covers all other color in an overcoat effect to create an all white coat. In its pure form, in which all offspring produced are white, blue eyes or odd eyed cats may well suffer from hearing loss, either partial or total. This is less likely to happen where one parent is white and the other colored.
White Spotting – A dominant gene that results in areas of color being curpressed by areas of white, creating the bi or tri colored cat. White spotting can range from a few white hairs creating a chest mark or a spot on the belly, to an almost complete absence of color. The van pattern surpresses color to form flashes on the head and a solid colored tail, whereas the harlequin shows a more spotted pattern of color on the body and legs as well.
Himalayan or Siamese – A recessive gene in which the color is restricted to the points of the cat, these being the face (mask), legs and tail. This pattern is usually associated with intense blue eyes
Burmese – A recessive gene to full color, but incompletely dominant to Siamese. The body appears to be a solid color, though of reduced intensity.
Tonkinese – A slightly pointed hybrid pattern created by a cross between Burmese and Siamese cats.
Cat Coat Quality And Length
Shorthair – Dominant gene restricting coat length. Strong guardhairs give impression of a crispness or sleekness of texture.
Semi Longhair – Recessive gene basically producing a long coated cat but with more noticeable length on neck, chest, rear legs and tai. Coat generally self maintaining.
Longhair – Produced by the same recessive gene as the semi longhair, but bred to produce a coat of extreme length, softness, silkiness of texture and requiring much human intervention to maintain it.
Wirehair – Dominant gene producing crimped, wiry, upstanding coat.
Rexed coat – Recessive group of genes, not always genetically compatible, producing a mostly tightly curled, soft textured coat.
Selkirk Rex Coat – Dominant gene which is the exception to the general Rex group, producing a shaggy, plush coated cat.
Sphynx – Recessive gene officially designated hairless but, in fact, producing a peach skin like coat which is quite different in quality from the truly hairless individuals still sometimes produced in devon rex cats. A hairless cat produced by a dominant gene is seen in Ukraine.