Cat Colour Genetics
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The following order of precedence for naming conventions has been used:
1. Use existing cat fancy terminology OR 2. Use the breed developer’s terminology (e.g. Salt and Pepper) OR 3. Borrow terminology from other livestock (e.g. belted, sheeted, cobweb) OR 4. Use descriptive plain English (swirled, skunk-stripe) OR 5. For seen-once mutations, use the location where it was observed (e.g. Finnish) OR 6. Use medical term (e.g. periocular leukotrichia) |
1. Self (Solid) Colours
There are 9 eumelanin-based (black-based) self colours and 3 phaeomelanin-based (red-based) self colours. The red-based colours are genetically solid, but because of the way the red pigment and non-agouti gene interact, they may have discernible tabby markings.
Self white (not shown) masks any underlying colour. The cat may be genetically black, genetically cream etc, but the presence of the white gene obscures the colour. Other self white cats are the result of extreme expression of the white spotting gene discussed later.
There are 2 late colour change genes that result in additional self colours: amber (Norwegian Forest Cats) and Russet (Burmese). These cause black pigment to gradually fade and become reddish. These charts are in a later section.
There are 9 eumelanin-based (black-based) self colours and 3 phaeomelanin-based (red-based) self colours. The red-based colours are genetically solid, but because of the way the red pigment and non-agouti gene interact, they may have discernible tabby markings.
Self white (not shown) masks any underlying colour. The cat may be genetically black, genetically cream etc, but the presence of the white gene obscures the colour. Other self white cats are the result of extreme expression of the white spotting gene discussed later.
There are 2 late colour change genes that result in additional self colours: amber (Norwegian Forest Cats) and Russet (Burmese). These cause black pigment to gradually fade and become reddish. These charts are in a later section.
2. White Spotting
The white spotting gene causes variable white markings. I've depicted this on a black cat, but any colour or pattern can have white markings. Generally speaking, a cat with one copy of the white spotting gene will be anywhere from 0% to 50% white while a cat with two copies of the gene will be anywhere from 50% to 100% white as shown on the chart.
The white spotting gene causes variable white markings. I've depicted this on a black cat, but any colour or pattern can have white markings. Generally speaking, a cat with one copy of the white spotting gene will be anywhere from 0% to 50% white while a cat with two copies of the gene will be anywhere from 50% to 100% white as shown on the chart.
2a. Other White Markings
Other white markings are not linked to the white spotting gene. Some are due to newly emerging gene mutations (e.g. the "Finnish" mutation, the roan mutation) and some are due to developmental anomalies or to illness/injury. Some of the terminology has been borrowed from other livestock that exhibits the pattern depicted.
Other white markings are not linked to the white spotting gene. Some are due to newly emerging gene mutations (e.g. the "Finnish" mutation, the roan mutation) and some are due to developmental anomalies or to illness/injury. Some of the terminology has been borrowed from other livestock that exhibits the pattern depicted.
3. Tabbies
The main tabby patterns are agouti (ticked/Abyssinian), mackerel, classic and spotted. Agouti (unpatterned) tabbies have ticked fur, but almost no striped markings except residual barring on the legs, tail, head and chest. Mackerel tabbies have thin striped markings while classic tabbies have blotched markings. Spotted tabbies can be due to broken mackerel stripes (in which case the spots are not so rounded) or to a spotting gene. The spotting gene breaks up the underlying mackerel or classic tabby pattern into spots. Some classic tabbies display a dark "cape" due to heavy markings; their agouti areas may be reduced to small patches on a black background.
There are also several modified tabby patterns produced by selective breeding, mutation or by crossing to a wild species. Strictly speaking, the Bengal marbled pattern should be a horizontally aligned clouded pattern inherited from the Asian Leopard Cat, but in most Bengals it is a slightly modified classic tabby pattern.
The tabby patterns and colours are shown in the 2 charts below. Red tabbies are variable in colour from sandy yellow (marmalade) through to the rich red found in show cats.
The main tabby patterns are agouti (ticked/Abyssinian), mackerel, classic and spotted. Agouti (unpatterned) tabbies have ticked fur, but almost no striped markings except residual barring on the legs, tail, head and chest. Mackerel tabbies have thin striped markings while classic tabbies have blotched markings. Spotted tabbies can be due to broken mackerel stripes (in which case the spots are not so rounded) or to a spotting gene. The spotting gene breaks up the underlying mackerel or classic tabby pattern into spots. Some classic tabbies display a dark "cape" due to heavy markings; their agouti areas may be reduced to small patches on a black background.
There are also several modified tabby patterns produced by selective breeding, mutation or by crossing to a wild species. Strictly speaking, the Bengal marbled pattern should be a horizontally aligned clouded pattern inherited from the Asian Leopard Cat, but in most Bengals it is a slightly modified classic tabby pattern.
The tabby patterns and colours are shown in the 2 charts below. Red tabbies are variable in colour from sandy yellow (marmalade) through to the rich red found in show cats.
3a. Ticked Tabby Colours
The standard colours manifest differently in ticked (unpatterned) tabbies.
The standard colours manifest differently in ticked (unpatterned) tabbies.
3b. Charcoal Bengal
An agouti gene inherited from the Asian Leopard Cat has given rise to another modified tabby pattern in the Bengal. The charcoal pattern reduces the amount of rufousing (red tones) in the coat and gives a dark "Zorro" mask on the face and a dark cape on the back.
An agouti gene inherited from the Asian Leopard Cat has given rise to another modified tabby pattern in the Bengal. The charcoal pattern reduces the amount of rufousing (red tones) in the coat and gives a dark "Zorro" mask on the face and a dark cape on the back.
4. Tortoiseshell, Tortoiseshell-and-White (Calico)
Tortoiseshell cats have a mix of a eumelanin colour with the corresponding phaeomelanin colour. This means dense with dense as in black with red, or dilute with dilute as in lilac/lavender with cream. The phaeomelanin-pigmented areas (red, cream or apricot) may show residual tabby markings. Where there is no white spotting or a low level of white spotting, the two tortie colours tend to be well brindled (intermixed). With greater degrees of white spotting, the colours form larger, well-defined areas. This is due to the way the pigmented cells spread in the developing embryo. In North America, tortie-and-white cats are known as calico.
Because the red colour is carried on the X chromosome and requires XX (female) genetic make-up, tortoiseshell is uncommon in male cats. It sometimes occurs as a result of developmental or genetic anomalies.
Tortoiseshell cats have a mix of a eumelanin colour with the corresponding phaeomelanin colour. This means dense with dense as in black with red, or dilute with dilute as in lilac/lavender with cream. The phaeomelanin-pigmented areas (red, cream or apricot) may show residual tabby markings. Where there is no white spotting or a low level of white spotting, the two tortie colours tend to be well brindled (intermixed). With greater degrees of white spotting, the colours form larger, well-defined areas. This is due to the way the pigmented cells spread in the developing embryo. In North America, tortie-and-white cats are known as calico.
Because the red colour is carried on the X chromosome and requires XX (female) genetic make-up, tortoiseshell is uncommon in male cats. It sometimes occurs as a result of developmental or genetic anomalies.
5. Tortoiseshell Tabby (with/without white)
Where tortie and tabby patterns are combined, the cat has different colour tabby patches e.g. black/brown tabby with red tabby instead of solid colour patches. These are known as patched tabbies in Europe and torbies in North America. When white markings are present, they may be called torbico in North America.
Where tortie and tabby patterns are combined, the cat has different colour tabby patches e.g. black/brown tabby with red tabby instead of solid colour patches. These are known as patched tabbies in Europe and torbies in North America. When white markings are present, they may be called torbico in North America.
6. Silver and Golden Series
Normal agouti hairs have bands of light and dark pigment corresponding to the coat colour e.g. black and brown bands for genetically black cats, red and cream bands for genetically red cats. When the silver gene is present, the light bands are pale grey or nearly white. In genetically tabby (agouti) cats, this results in a tabby or ticked pattern on a silver base. Depending on the degree of ticking, this ranges from tipped (chinchilla) to shaded to silver tabby. When the silver gene is combined with a self (non-agouti) colour, the result is smoke. Some smoke kittens may show a residual tabby pattern until they get their full adult coat.
The mechanism for golden is generally analogous to silver, but appears due to the wide band gene that lightens and brightens the background colour of agouti regions of the coat. Therefore it is debatable whether golden smokes exist. Other genes can give the impression of golden e.g. high levels of rufousing in breeds with wildcat ancestry.
Normal agouti hairs have bands of light and dark pigment corresponding to the coat colour e.g. black and brown bands for genetically black cats, red and cream bands for genetically red cats. When the silver gene is present, the light bands are pale grey or nearly white. In genetically tabby (agouti) cats, this results in a tabby or ticked pattern on a silver base. Depending on the degree of ticking, this ranges from tipped (chinchilla) to shaded to silver tabby. When the silver gene is combined with a self (non-agouti) colour, the result is smoke. Some smoke kittens may show a residual tabby pattern until they get their full adult coat.
The mechanism for golden is generally analogous to silver, but appears due to the wide band gene that lightens and brightens the background colour of agouti regions of the coat. Therefore it is debatable whether golden smokes exist. Other genes can give the impression of golden e.g. high levels of rufousing in breeds with wildcat ancestry.
6a. Silver and Golden Torties & Tabby-Torties
6b. Sunshine and "Bimetallic"
In Persians, Exotics and British Shorthairs, golden results from two copies of the recessive inhibitor gene combined with the wide band gene. In Siberians, the Sunshine colour is also inherited recessively but is not due to the inhibitor gene. It brightens the agouti (ticked) areas of the coat. The effect is often patchy on the coat. Sunshine silver looks different from a silver with rufism; the nose leather is pinkish unlike that of a tabby cat. The red colour of a sunshine red tabbies and sunshine torties is brighter and the paws are lighter. The absence of pigment in the sunshine tabbies extends beyond the edges of the nose leather so they have no nose-liner and have whitish fur at the bottom of the nose.
In Persians, Exotics and British Shorthairs, golden results from two copies of the recessive inhibitor gene combined with the wide band gene. In Siberians, the Sunshine colour is also inherited recessively but is not due to the inhibitor gene. It brightens the agouti (ticked) areas of the coat. The effect is often patchy on the coat. Sunshine silver looks different from a silver with rufism; the nose leather is pinkish unlike that of a tabby cat. The red colour of a sunshine red tabbies and sunshine torties is brighter and the paws are lighter. The absence of pigment in the sunshine tabbies extends beyond the edges of the nose leather so they have no nose-liner and have whitish fur at the bottom of the nose.
7. Colourpoints
There are 3 levels of colourpointing seen in cats. These are all due to temperature dependent albinism genes that cause cooler parts of the body to develop darker pigment. The first is the familiar high-contrast "Siamese" pattern known to geneticists as colourpoint or Himalayan pattern. The second is the low-contrast Burmese colour restriction, often referred to as sepia pointing (because it was first seen in brown/sepia Burmese). Intermediate between these is the mink pattern (Tonkinese colour restriction) caused when the Siamese and Burmese colour restriction genes interact.
The points may be solid, tabby or tortie colours. With Siamese colour restriction the torso is a shade of cream or ivory although some cats show "breakthrough markings" especially as they age. With Burmese colour restriction, the torso is marked with a slightly paler version of the colour and pattern. With Mink, the level of colour/pattern displayed on the torso is intermediate between those extremes.
There are 3 levels of colourpointing seen in cats. These are all due to temperature dependent albinism genes that cause cooler parts of the body to develop darker pigment. The first is the familiar high-contrast "Siamese" pattern known to geneticists as colourpoint or Himalayan pattern. The second is the low-contrast Burmese colour restriction, often referred to as sepia pointing (because it was first seen in brown/sepia Burmese). Intermediate between these is the mink pattern (Tonkinese colour restriction) caused when the Siamese and Burmese colour restriction genes interact.
The points may be solid, tabby or tortie colours. With Siamese colour restriction the torso is a shade of cream or ivory although some cats show "breakthrough markings" especially as they age. With Burmese colour restriction, the torso is marked with a slightly paler version of the colour and pattern. With Mink, the level of colour/pattern displayed on the torso is intermediate between those extremes.
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7a. Ragdoll & Bicolourpoints
Some breeds combine colourpointing (usually Siamese colour restriction) with the white spotting gene. Breeders generally prefer a low level of white spotting that does not wholly obscure the coloured points. Separate genes are believed to control the uniformly expressed white mitting in certain breeds. |
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8. Non-Extension Gene: Amber and Russet
These two genes cause the eumelanin to fade, leaving behind reddish tones. Amber (in Norwegian Forest Cats) causes black to fade to amber, and blue to fade to light amber. The kittens are born black or blue and fade as they reach adulthood, starting with the dorsal region. Russet is found in the Burmese; kittens are born an unusual lilac/chocolate colour and eventually turn reddish. The progression of the colour change is depicted in the chart below.
These two genes cause the eumelanin to fade, leaving behind reddish tones. Amber (in Norwegian Forest Cats) causes black to fade to amber, and blue to fade to light amber. The kittens are born black or blue and fade as they reach adulthood, starting with the dorsal region. Russet is found in the Burmese; kittens are born an unusual lilac/chocolate colour and eventually turn reddish. The progression of the colour change is depicted in the chart below.
9. Pink-Eyed Dilution
Pink-eyed dilution was reported by NB Todd NB in 1961. "A pink-eyed dilution in the cat" (Journal of Heredity 52, pg 202). The usual type of dilution found in cats is blue dilution which turns black into grey. A second type of dilution seen in some mammals is "pink-eyed dilution" which gives a bluish-tan/fawn coat and also depigments the eye, giving a pink or ruby appearance. According to Todd, this has been reliably reported only once in cats when a pink-eyed female with a light tan coat was produced. None of her kittens survived so pink-eyed dilution in cats seemed to have been lost. In 2015, a pink-eyed Sphynx kitten of unidentifiable colour appeared in Australia. It matched the description of bluish-tan/fawn colour andhad gold irises with ruby red pupils. Genetic testing ruled out the known dilution and albinism genes.
Pink-eyed dilution was reported by NB Todd NB in 1961. "A pink-eyed dilution in the cat" (Journal of Heredity 52, pg 202). The usual type of dilution found in cats is blue dilution which turns black into grey. A second type of dilution seen in some mammals is "pink-eyed dilution" which gives a bluish-tan/fawn coat and also depigments the eye, giving a pink or ruby appearance. According to Todd, this has been reliably reported only once in cats when a pink-eyed female with a light tan coat was produced. None of her kittens survived so pink-eyed dilution in cats seemed to have been lost. In 2015, a pink-eyed Sphynx kitten of unidentifiable colour appeared in Australia. It matched the description of bluish-tan/fawn colour andhad gold irises with ruby red pupils. Genetic testing ruled out the known dilution and albinism genes.
10. Recently Noted Mutations of Red Pigment
These colours are under investigation and may not be true mutations, just slight modifications of how known genes are being expressed visually. For now I'll use the term "mutation" in a very loose sense. All of these occur on cats that are genetically red. The colours visuallyb resemble eumelanin (black pigment) colours even though no black pigment is present. One mutation/modification turns red pigment into a rich cinnamon colour. Another turns the ground colour of red tabbies to a bluish/lilac colour. This may also be responsible for the bluish tones at the extremities of some red cats.
These colours are under investigation and may not be true mutations, just slight modifications of how known genes are being expressed visually. For now I'll use the term "mutation" in a very loose sense. All of these occur on cats that are genetically red. The colours visuallyb resemble eumelanin (black pigment) colours even though no black pigment is present. One mutation/modification turns red pigment into a rich cinnamon colour. Another turns the ground colour of red tabbies to a bluish/lilac colour. This may also be responsible for the bluish tones at the extremities of some red cats.
11. Eye Colours
Eye colours are associated with coat colours. Random-bred cats have the widest range of eye colours while the eye colours in pedigree breeds have been restricted by selective breeding. In other breeds, the gene that causes the colour/pattern also affects the eye colour e.g. blue eyes in colourpointed (Siamese pattern) cats.
Eye colours are associated with coat colours. Random-bred cats have the widest range of eye colours while the eye colours in pedigree breeds have been restricted by selective breeding. In other breeds, the gene that causes the colour/pattern also affects the eye colour e.g. blue eyes in colourpointed (Siamese pattern) cats.
12. Shimmering Effects
Shimmering effects either affect the structure of the fur or are due to white or translucent tipping of the hairs. Effects seen to date are grizzle (in Chausies), silver tipping (in Korat and Russian Blue) and Satin (in Tennessee Rex). Sparkling effects are also found in the Bengal.
Shimmering effects either affect the structure of the fur or are due to white or translucent tipping of the hairs. Effects seen to date are grizzle (in Chausies), silver tipping (in Korat and Russian Blue) and Satin (in Tennessee Rex). Sparkling effects are also found in the Bengal.
13. Posited Tan Series
This gene has not yet been seen in cats, but in dogs it is an allele (alternative gene) at the agouti locus. This chart is a suggestion of how colour-and-tan cats would look if the mutation occurred. Theoretically it could be combined white spotting, colourpointing and silver/golden series. The possibility of tabby-and-tan patterns would depend on how the tan gene, if it occurred in cats, interacted with existing genes.
This gene has not yet been seen in cats, but in dogs it is an allele (alternative gene) at the agouti locus. This chart is a suggestion of how colour-and-tan cats would look if the mutation occurred. Theoretically it could be combined white spotting, colourpointing and silver/golden series. The possibility of tabby-and-tan patterns would depend on how the tan gene, if it occurred in cats, interacted with existing genes.
14. Posited Merle Series
This gene has not yet been seen in cats, but is found in dogs. Broadly speaking it manifests as patches of dense colour on the equivalent dilute e.g. black patches on a blue background, black patches on caramel, red patches on cream. This is different from tortie where the patches are a mix of a black-based colour with a red-based colour.
Theoretically it could combine with existing colours and patterns, but would only show to good effect on dilute-coated cats e.g. a blue/cream tortie with black patches, or a lavender (lilac) tabby with chocolate patches. Theoretically these could also be combined white spotting, colourpointing and silver/golden series. The chart shows how merle might manifest in cats should the mutation occur.
This gene has not yet been seen in cats, but is found in dogs. Broadly speaking it manifests as patches of dense colour on the equivalent dilute e.g. black patches on a blue background, black patches on caramel, red patches on cream. This is different from tortie where the patches are a mix of a black-based colour with a red-based colour.
Theoretically it could combine with existing colours and patterns, but would only show to good effect on dilute-coated cats e.g. a blue/cream tortie with black patches, or a lavender (lilac) tabby with chocolate patches. Theoretically these could also be combined white spotting, colourpointing and silver/golden series. The chart shows how merle might manifest in cats should the mutation occur.
15. Imported Colours/Patterns
Some colours and patterns have been imported from a wildcat ancestor. Some of these have already been detailed e.g. charcoal pattern Bengals, grizzle pattern Chausies and the rosetted and marble/clouded pattern seen in several hybrids breeds. The following are 2 novel patterns derived from wildcat x domestic cat crosses. The Rusty Spotted Cat hybrid illustration is based on descriptions of purported hybrids. The Sand Cat hybrid illustration is based on photographs of F1 kittens.
Some colours and patterns have been imported from a wildcat ancestor. Some of these have already been detailed e.g. charcoal pattern Bengals, grizzle pattern Chausies and the rosetted and marble/clouded pattern seen in several hybrids breeds. The following are 2 novel patterns derived from wildcat x domestic cat crosses. The Rusty Spotted Cat hybrid illustration is based on descriptions of purported hybrids. The Sand Cat hybrid illustration is based on photographs of F1 kittens.
17. Colour pattern Mutations in Big Cats
These have been depicted on a spotted big cat as this is the most common pattern, however a number of these mutations occur on striped, rosetted or clouded patterns as noted on the chart. This chart is included for comparison and general interest.
These have been depicted on a spotted big cat as this is the most common pattern, however a number of these mutations occur on striped, rosetted or clouded patterns as noted on the chart. This chart is included for comparison and general interest.
Similar color charts have appeared in Wright & Walters (The Book of the Cat, 1980) and in Robinson's Genetics (1977 onwards) and all of this information on this page has been reproduced with credit to Sarah Hartwell.