Cats have been around for several millennia, and with them come the colors that we loved.
The basic principles of cat color and pattern genetics are simple but there is a huge variety possible. This is due to the modifiers, factors, and mutations that have resulted in the hundreds of subtle and interesting colors we see in cat coats today.
Many of the more esoteric colors have been refined through the selective breeding process practiced by those involved with pedigreed cats. Knowledge of genetic principals is a helpful tool. Understanding feline color and pattern terms is an important way in which random-bred cats can be identified.
Why Should You Care About Cat Colors and Patterns?
Should a cat become lost it is imperative for an owner to be able to give the local shelters an accurate description of the cat.
Instead of calling a cat a “gray tiger striped cat” if he is described as a “blue mackerel tabby domestic short-hair, neutered male about two years old, with hazel eye color and a slim long body” he has a much better chance of being identified on intake at the shelter.
Or a “Siamese’ cat with stripes” could be described as a “seal lynx-point color-point domestic longhair, 3-year-old spayed female, with classic tabby ghost markings on her body, gold eye color, and a stocky body”.
Shelter staff and volunteers can help make cat color/pattern description terminology better known if they will use accurate terms on the adoption papers when the cat is transferred. Cat owners like to be able to describe their cat properly.
A few of the cat colors in the Cat Fanciers’ Association Show Standards have historical significance(i.e. “ebony” is used instead of “black” in the Oriental and Ocicat breed standards) so there is little chance of getting total agreement on terminology consistency. Nevertheless, the CFA standards remain the best place to find accurate color and pattern descriptions.
Cat Genetics in a Nutshell
Dominant genes and recessive genes are primarily responsible for cat colors and patterns.
When a cat inherits a dominant gene from both parents he is homozygous for that gene and will have the appearance of the dominant color and/or pattern.
If he inherits a dominant gene from one parent and a recessive gene from the other parent then that cat will reflect the appearance of the dominant gene but will be a heterozygous carrier of the recessive genetic color or pattern.
When two cats carrying the same recessive genes mate, those offspring who inherit these genes from both parents will be homozygous and have the appearance of the recessive gene.
One dominant gene is responsible for tabby patterns. All tabbies are agouti “A”(the recessive gene “a” results in solid coat color)
Three dominant genes are needed to make a cat coat color appearance:
- Pigment – “B” is full black color (the recessive genes “b” and “b l” result in brown cats and light brown or the cinnamon-colored cats)
- Color – “C” is full intensity (the recessive genes “c s” and “c b” are reduced intensity and represent the albino series giving the Siamese and the Burmese pointed color spectrum)
- Density – “D” is the full packing of pigment discs (the recessive gene “d” is the dilute factor that results in modifying black to blue and red/Orange to cream, brown/chocolate to lilac and cinnamon to fawn.)
All cats are black except when they display the mutated sex-linked orange gene “O”, which eliminates the black pigment.
The O gene is on the sex chromosome X. Males are XY so they can be black or orange but not both. Females have two X chromosomes so they can be black or orange or both colors, as is the case with tortoiseshell cats and calicoes. Because the O gene is on a different chromosome than the other colors and patterns the non-agouti gene does not work. Thus all orange (red) cats appear to be tabbies and the red coat patches on a tortoiseshell or calico will also show tabby marks.
Every other color is the result of various genetic factors acting on these two basic colors – black and red/orange.
All Cats are Tabbies
The expression of a pattern is only seen when the dominant agouti A gene is present. Should a cat inherit the recessive non-agouti gene “a” from both parents, then their appearance will be full color.
However, cats do not lose their underlying tabby pattern and they can pass on its genetics. Often young kittens who are solid colored will show their tabby pattern lightly until their adult coat grows in.
Also, even adult cats seen in bright sunlight can also sometimes display a faint underlying tabby pattern.
There are 4 traditional tabby markings:
- ticked(most dominant)
- classic or blotched
Because the black gene is dominant, tabby cats will have black markings on the surface of their coat. They also have marks on their faces, including clown lines around the eyes, swirls on their cheeks and an ‘M’ on their forehead. They usually have several dark necklace marks, leg bracelets and tail banding with the tip of the tail black. Between the stripes is agouti ticking. These cats are called brown tabbies because the ground color between the stripes ranges from a light tawny brown to a rich burnt sienna tone.
The recessive density gene (the dilute factor) causes the black tabby markings to be blue. Orange/red tabbies become cream; chocolate is changed to lilac and cinnamon to fawn.
Ticked tabbies (Ta) have no stripes but instead, show the agouti ticked pattern all over their body. Each hair is banded with the base color, then black, base color and ending with a black tip. The other characteristic tabby markings, such as necklaces, facial marks, leg and tail markings will all be there. In the case of the Abyssinian cats, a well-known breed with agouti ticked tabby pattern, the chest necklaces, and the leg and tail stripes have all been eliminated with the facial marks maintained. This took many years of selective breeding. It meant choosing cats with the least or the lightest marks considered undesirable until there were none.
Mackerel tabbies (T) have vertical stripes on the body with a solid dark spine line plus the characteristic tabby facial, chest, leg and tail markings.
Classic tabbies (Tb) have bold swirls on their body, ideally with a “bulls-eye” on each side (an unbroken circle with a large spot or blotch in the middle). This pattern includes a butterfly marking over the shoulders and a dark spine line flanked by a line on each side, plus the other characteristic tabby markings.
Spotted tabbies (Sp) have spots randomly placed on the body; These can be small or large and the pattern includes a dark broken spine line and all of the other characteristic tabby markings.
Females of any tabby pattern can be patched tabbies if they have inherited the sex-linked orange gene, which adds splashes of red throughout the coat.
Original Wild Cats' Pattern Evolvement
The original wild cat ancestor of all domestic cats has been determined to be Felis Sylvestris Lybica. These cats gravitated to the barns when humans became agrarian thousands of years ago and they eventually became tame/social in Egypt. They have a tawny brown coat with agouti ticking and sometimes light striping on their bodies, making them well suited to a desert environment.
Later when some of the domesticated cats migrated to Europe the influence of their matings with the European Wildcat resulted in more prominent mackerel tabby markings, which better camouflaged the cats in a wooded landscape.
Effect Of Mutations On Cat Coat Colors and Patterns
The “seven ancient mutations” occurred hundreds, or perhaps thousands, of years ago. All but one, the gene for long hair, affected color or pattern.
- Classic tabby pattern is recessive to the original mackerel and ticked.
- Non-agouti is recessive to tabby and causes the pattern to not be seen (solid color).
- Sex-linked orange gene changes black to red.
- Dilute factor is recessive to full density and causes black to become blue, red to become cream, etc.
- Pie-bald spotting factor is an “incomplete or semi-dominant” gene because it is affected by modifying genes. It causes small or large areas of white resulting in patterns such as tuxedo, bi-colored, “Van” patterned or calico.
- Long hair is recessive to short hair.
- Dominant white masks the expression of all other color genes; however, the actual underlying color of the cat can still be passed on to its offspring.
Later mutations also further affect color/pattern of cats.
- Albino series genes are recessive to full-color intensity. These include the Siamese, Burmese, Tonkinese, Balinese, Javanese, Himalayans and Colorpoint Oriental pedigreed cats as well as the many random-bred household pet cats with pointed coloring.
- Inhibitor gene is dominant that suppresses the pigment in the hair shafts causing white on the shaft. In combination with tabby markings, it creates the silver tabbies (black gene) or the cameo tabbies (red/orange gene) and cats with color only on the tips of the hair shafts (shaded silver and chinchilla or shaded cameo and shell cameo). When the Inhibitor gene is combined with the non-agouti “a” gene then we see the smoke coloring. There is nothing more dramatic or surprising than a solid color black cat with pure white underneath that is only seen when the coat is parted.
- Chestnut (dark brown b gene) and the cinnamon (light brown bl gene) are both recessive to the full pigment black B gene but dominant to the recessive lilac or lavender and in the case of cinnamon the color fawn.
Polygenes and Other Variables Affecting Color
Polygenes are continuous in their variation from one extreme to the other. They either enhance or diminish color tones, “Rufous” polygenes can enhance/change a light ginger-yellow orange tone to a rich deep red color. Or the natural golden hue of a brown tabby (the black gene) undercoat can become the deep burnt sienna color of a pedigreed American Shorthair or ruddy Abyssinian. Diminishing polygenes can change dark slate blue to a soft powder blue tone, or make a silver coat free of yellow “tarnishing”. Manipulation of polygenes is especially used by breeders of pedigreed cats.
Bi-Colored cats are the manifestation of the pi-bald white spotting factor. This is another continuous variable inherited as an “incomplete” or a “semi-dominant” gene. When the amount of white is small, perhaps a nose blaze and a small white bib, it is referred to as “low-grade” spotting. If the cat is almost entirely white with the only color on the tail and a few spots on the head with one or two spots on the body this is “high-grade” spotting. The “Van” patterned cats are examples. Most bi-colored cats are “medium-grade”. They have about 50% white with white bellies and legs and large areas of solid color or tabby markings on their bodies. Tortoiseshell and white and calicoes are referred to as tri-colored cats.
It is interesting that the full spectrum of colors from hazel brownish through emerald green and yellow to deep gold and copper orange is all controlled by polygenes. The recessive colors of the albino series give these cats blue eye color and the dominant white gene is also associated with blue eyes. The brilliance and intensity of the blue eye color tone are also controlled by polygenes. The phenomenon of “odd eye” color (one eye is gold, copper or green and the other is blue) is also possible with certain coat colors including dominant white.
Random Bred Cats With Similar Colors And Patterns as The Pedigreed Breeds
Originally there were seventeen varieties of “Siamese cats” documented in the Cat Book of Poems written over 200 years ago and discovered in 1767. The cats best known in the kingdom of Siam (now Thailand) were the solid color blue cats (Korats), the seal pointed cats (“Siamese”), the “copper” cats (today’s Tonkinese), the all white cat (Khao Manee), the all black cat and a piebald spotted cat with nine black spots on a white body. The seal pointed cats were considered special. These cats are black, but the effect of the reduced intensity gene that modifies all the point colors changes black to a dark seal. The facial mask, ears, legs, and tail are all dark while the body color is a clear light fawn tone.
The seal points were known as the “Temple Cats of Royalty”. They sat on the castle walls and with their load raucous voices would warn of any distant enemy warriors approaching. They were only given to ambassadors or other highly positioned people. In the late 1800s several pointed cats were imported to England and a few to America. Two seals pointed Siamese were exhibited in the 1871 Crystal Palace show in London and Chocolate pointed cats were exhibited at shows in England in 1899.
When the Siamese cats were seen in America they became very desirable and they were often cross mated to domestic shorthairs. This is why the color-pointed genes are still prevalent in the random-bred population. However, the body and head type differ dramatically from those of the pedigreed Siamese.
Maine Coon cats were the working cats in New England for well over 100 years. They have a large color and pattern spectrum. When settlers started to move to the western states they took their cats with them and it is believed that this is how many of the colors and patterns spread across the country and into the random-bred population.