Rare cat colours at a glance
- Calico or tortoiseshell (male)
Cats come in a huge range of cat colours and patterns, which is controlled by genes, gene modifiers, gender and even temperature in pointed cats.
Cats have 19 pairs of chromosomes, which are inherited from the mother and father. Each chromosome DNA (deoxyribonucleic acid), which contains the instructions an organism needs to develop, live and reproduce. Genes come in pairs, one from the mother and one from the father and can be dominant or recessive. A dominant gene overrides a recessive gene, and two copies of a recessive gene must be present for that trait to develop.
There are only two true colours in cats, black and red. Every other coat colour is a deviation of those two colours. Black and red are dominant, and therefore only one copy of the gene is needed for the cat to show these colours.
Common cat colours and patterns
- Black and white
- Brown tabby
- Grey tabby
- Brown or grey tabby and white
- Red and white
- Black and red (tortoiseshell)
- Black, red and white (calico or caliby)
- White (dominant)
The default colour and pattern is the mackerel tabby in either brown or grey. This is seen in the cat’s common ancestor, felis silvestris lybica and is widespread among the domestic cat population. Variations of the mackerel pattern are the classic tabby and the spotted tabby.
The tabby is the most common colour and pattern to occur in cats.
The selfs (or solid) cats occur in six basic colours, black, blue, chocolate, lilac (also known as lavender), cinnamon and fawn. Clumps of pigmentation are distributed evenly in the hair shaft, which gives the illusion of a black, chocolate or red cat. Dilute cats have enlarged pigment granules that are deposited unevenly in the hair shaft resulting in clumps of varying size along the length of the hair shaft which makes the cat appear lighter. Black becomes blue (grey), and red becomes cream.
Dense colours (black, red) are dominant over the recessive dilute colours (blue, lilac and cream) and are therefore much more commonplace as the cat only needs to inherit one gene for the dense colour to appear.
Also known as piebald, the bicolour coat consists of one colour (black, brown, blue, red) and white and is caused by the white spotting gene. Some cats may only have a few white hairs, others will have a 50-50 mix of colour and white, and some are predominantly white with a small amount of the other colour. The well-known tuxedo cat (black and white) is a bicolour.
Bicolour cats can be solid and white (most commonly black, brown or blue) or tabby and white.
Less common cat colours
- Pointed (Himalayan)
- Burmese sepia
- Tonkinese mink
- Dilute tortie or calico
Dilute selfs are less common than the dominant colours of black and red. Blue (grey) is the most common dilute colour and occurs in purebred as well as mixed breed cats. Lilac, fawn and cream are less common dilute colours and mostly found in purebred cats, especially the Burmese, Oriental and British Shorthair, but can include any breed with no coat colour or pattern restrictions including the Persian, Exotic, British Longhair, Oriental Longhair, Devon Rex, Cornish Rex, Munchkin, Sphynx.
The dilute modifier (dm) gene causes a further washing out of dilute colours and caramelises them.
|Chocolate (brown)||Lilac||Lilac-based caramel|
Blue (grey) is dilute black, the colour is chemically black (eumelanin), but melanin granules clump in the hair shaft resulting in colourless areas which allow more light to pass through the hair and lightening the colour. The British Blue, Russian Blue, Korat and Nebelung are the most well-known breeds with blue coats, but the colour can also occur in mixed-breed cats.
The brown coat colour (b) is a variation of black (B) coat colour and is caused by a mutation that leads to reduced amounts of black pigment which causes them to appear brown and is recessive to black. Chocolate is frequently referred to as a rare colour, but it is quite common in purebred cats, especially Orientals and British Shorthairs.
Two mutations of the B gene have been identified, b (brown or chocolate) and bl (light brown or cinnamon). The chocolate (b) allele is dominant over the cinnamon (bl) allele. Since the B gene is dominant over the locus, cats heterozygous for it ( B/b or B/bl genotype), carry chocolate or cinnamon gene but it cannot be recognized based on phenotype.
Lilac is dilute chocolate and bears the same relationship to brown as blue does to black. It is seen most frequently in purebred cats, especially the Burmese, Oriental and British shorthair. The coat colour is a pale grey with a rich pink tone.
The cinnamon coat is a warm-brown shade compared to the rich brown of the chocolate colour and is produced by a second recessive allele (variation of a gene) of B (black) which causes an elongation of the pigment granule and is denoted by the symbol bl.
Fawn is dilute of cinnamon (above) and resembles the lilac coat colour, but is lighter. The non-agouti cinnamon and fawn colours are seen most often in the Oriental and British Shorthair.
Pointed (Himalayan gene)
The Siamese is the most well known of the pointed breeds, with its characteristic dark points on a light background. The pointed colour is also found in other cat breeds as well as mixed-breed cats.
This unusual coat pattern is caused by a gene modifier that prevents the expression of the coat colour on warmer parts of the body. The gene responsible for the Siamese colouration is known as cs and is recessive. Therefore both the mother and father must carry the cs gene for it to be passed on.
Burmese ‘sepia’ gene
The Burmese cat has a slight variation of the pointed gene, they still have points on the extremities, but the body is darker. The gene responsible is known as cb, the lower case letters tell us that it is a recessive gene. This colouration is most prominent on the chocolate (champagne) Burmese and brown (sable) Burmese.
Tonkinese ‘mink’ gene
The Tonkinese is a cross between the Burmese and Siamese and three patterns; seal, mink and solid. Seal has the characteristic appearance of the Siamese coat, solid has no points and mink is a blend of the Burmese/Siamese coat pattern. Once again, this pattern is only found in the Tonkinese which also makes it relatively rare. The genetic code for the Tonkinese is cs/cb
The photo below is my own two Tonkinese cats, Norman on the left is a seal Tonkinese and Calvin on the right is a mink. The fur on his body is a cream colour compared to almost white on Norman.
The smoke occurs due to a combination of the inhibitor gene which produces a white undercoat.
The van colouration is most widely recognised in the Turkish Van but can be found in mixed breed cats as well. The van coat pattern is essentially a bi-colour, however, the cat is mostly white with splashes of red or black between the ears and on the tail.
The Chinchilla coat pattern is exclusive to the Persian cat (sometimes referred to as Chinchilla Persian), and is characterised by silver-tipped hairs with a pale base that is caused by the dominant melanin inhibitor gene (I/i) and is a tabby variant.
Dilute tortie or calico
The tortoiseshell and calico colour/pattern is reasonably common in mixed breed cats as well as some purebreds. What is interesting is that only female cats can be tortoiseshell or calico. This interesting colour combination contains both red and black or brown, and white if the cat is calico.
Dilute tortoiseshell or calico cats are blue and cream, or blue, cream and white.
The cream coat colour is a dilution of red and is pale with a slight rusty hue. As with most of the other dilutions, cream is uncommon among mixed-breed cats but is becoming more commonplace among purebred cats.
- Burmese russet
- Burmese cinnamon
- Norwegian Forest cat Amber
- Bengal charcoal
- Bengal melanistic
- Male calico or tortoiseshell
Russet is a relatively new coat colour that appeared in a litter of kittens born in New Zealand in 2007 and is thought to be a mutation of the extension gene. The colour develops with age and is characterized by progressive amounts of red pigment on the head and dorsal surfaces.
Cat breeder and geneticist Rod Hitchmough identified a different colour which was characterised by a warm brown, which differed from the traditional brown (sepia) in the Burmese cat.
In Norwegian Forest Cats, a recessive mutation in the melanocortin 1 receptor gene leads to the gradual replacement of black pigment in the coat with yellow pigment, producing amber colouration.
White is seen relatively often in cats, and can occur in one of three ways.
- The dominant W gene which masks the effect of other colour genes. So, a cat may be genetically black or red, but the inhibits the production of normal pigment cells during embryonic development.
- The white spotting gene which affects the entire coat, the eyes may be blue or non-blue.
- True albinos are extremely rare, and is caused by a complete absence of melanin in the hair and eyes and is recessive to full colour (C/C or C/c) represented as c/c for blue eyed albinos or ca/ca . for pink-eyed albinos.
Calico or tortoiseshell (male)
Calico and tortoiseshell cats are commonplace among both purebred and mixed breed cats, but is almost exclusively found in female cats. That is because the orange gene is only found on the X chromosome. So, if a male inherits the O gene, he will be red. The female has two X chromosomes, and therefore may inherit one O gene and one B (black) gene, in which case she will be red and black. If she also carries the white spotting gene, she will be a calico.
The incidence of calico or tortoiseshell in male cats is estimated to be in 1 in 3,000 and may be caused by chimerism (two distinct cell lines in the one body), or Kleinfelter syndrome where the male has an extra X chromosome, so he is XXY instead of XY.
The charcoal is found in the Bengal breed and is characterised by a darker face mask and thick dorsal stripe. It is the result of a combination of the domestic cat non-agouti variant and the Asian Leopard Cat agouti variant.
Also known as a black Bengal, the melanistic Bengal has a black coat with black spots or marbles (black on black), that is caused by the recessive non-agouti gene.
Vitiligo isn’t a coat colour or pattern, rather it is an extremely rare autoimmune condition that causes the destruction of the pigment-producing melanocytes which causes the skin and fur to lose its pigmentation (called depigmentation) in patches giving the fur a unique dappled pattern. This progressive condition starts at a young age and as the melanocytes are destroyed, the skin and fur turn white.