WHAT COLOUR IS MY CAT - THE INDEFINABLE COLOURS
I'm often sent photos asking "what colour is my cat – I've looked all over the web and he isn't any colour I can find!" Most of these indefinable colours are colours that are simply unfamiliar to the owner. A surprising number of people mistake classic-tabby-and-white, especially those with lots of white, like the one shown here, for calicos and I have to disappoint them that they haven't found an elusive male calico.
Although new colours pop up from time to time due to mutation or hybridisation, most of the apparently indefinable colours can be worked out once you are familiar with the basic patterns and colours. Those that are completely new are termed X-colours until the mutation is better understood and the colour gets a proper name in the cat fancy.
Although most people are familiar with well-patched or well-brindled torties, torties can actually vary from almost completely black with just a few streaks of orange, through to orange with just a few spots of black. Some breeders may not realise they have a tortie cat until she has "genetically impossible kittens." This sort of tortie is known as a cryptic tortie (hidden tortie). One thing you'll notice is that as the amount of white increases, the tortie colours separate into more distinct patches. Little or no white = more brindling. Lots of white = more distinct patches.
Most people are familiar with tortoiseshell and tortie-and-white cats (known as calico in North America) in the black/red and blue/cream varieties, but there are less common torties as well that combine chocolate or cinnamon with red or lavender, or combine fawn with cream. These less common ones are found mainly in pedigree cats, but now and again one turns up in randombred pets and strays. I've called these "unexpected colours."
To confuse matters further, tortoiseshell cats can have a silver undercoat, making them smoke torties/calicos. More on silver later, but here's an unusual tortie smoke example:
This photo from Leva Cygnet shows one of the more unusual colours that can crop up randomly. The mother was a smoke tortie-and-white longhaired female and the presumed father a pale red or dark cream tabby male who is apparently the only free-roaming intact male in the area. The kittens included a chocolate male called Mocha, a black smoke male (who will be longhaired), a ginger female, a ginger male and a chocolate tortie - quite unusual in the randombred population as well as being smokes with a silver undercoat (visible when the fur is parted). This means that one or both of the parents carried the recessive chocolate gene - unusual enough that quite possibly the parents are related. The chocolate gene ultimately traces back to Siamese cats, but has been introduced by cat fanciers into various other cat breeds. It would have entered the random-breeding population through unneutered purebreds and being recessive to black can go unnoticed for may generations. Mocha grew into a large chocolate smoke male whose appearance hinted at Burmese ancestry.
Most of my "what colour is this?" queries turn out to be unusual tortie cats - either tabby-torties or colourpoint-torties - with or without white patches. Most owners are familiar with black/red tortoiseshell/calico and with blue/cream tortoiseshell/calico but there are a number of other colour combinations. Even judges may not be familiar with the more uncommon tortie colours for example chocolate tortie or lilac-cream tortie. In this this article I often use black/red or blue/cream torties in examples because these are the most esily recognisable colourways.
Tabby-torties have the tabby pattern overlaid on the tortie pattern. In ordinary black/red or blue/cream torties, there is a tabby pattern visible in the red or cream areas. This is normal and some cats more pronounced markings than others in those areas. In tabby-torties, instead of solid black or solid blue areas, the cat has brown-tabby or blue-tabby areas. The red or cream areas have much clearer tabby markings which may be ticked (Abyssinian), swirled (classic), striped (mackerel) or spotted. A combination of swirled tabby markings and random tortie patches can give a multicolour coat of red, cream, brown and black with the mix of colours making it hard to see the tabby markings (tip: if you set your camera to monochrome mode and take a photo, you will see the tabby markings more clearly.).
Now lets add colourpoint into the tortie mix! Colourpoint means those patterns where the body is paler than the head, tail and legs. In these cats, pure black is replaced by dark brown ("seal"). Here I have used "colourpoint" for Siamese pattern, "mink" for Tonkinese pattern and the last is "Burmese pattern". Colourpoint torties have a mix of the tortie colours on a Siamese type coat . The colours are darkest on the legs, tail and head. The body may not be completely cream as you might expect, but instead it has a paler version of the those tortie colours. The body tends to darken as the cat grows older. Once again, if you add tabby to the mix and you get a cat that has red/cream plus several shades of blue or brown on its coat (as shown by the cat in this photo).
Mink torties have less contrast between the body and points. It's a halfway stage between Siamese pattern and Burmese pattern. The mink colour range is found in the Tonkinese breed, but mink torties and mink tabby-torties can turn up in random-bred cats where those Siamese and Burmese genes have somehow both ended up in the mix. If the gene for silver is also present, the cat has a silvery undercoat/background colour.
Burmese torties are probably more familiar in Britain than in the USA. This colourway is recognised in the European Burmese breed. These cats have a combination of tortie with the Burmese (low contrast) colourpointing and this gives a rather pastel effect (hence the other name "sepia"). Burmese-type torties and tabby-torties sometimes appear in random-bred cats. Once again, if the gene for silver is also present, the background/undercoat colour is silvery as in the cats below. Any of the tabby patterns can combine with tortie - ticked, classic, mackerel or spotted - and any of these can have the silver undercoat.
Sometimes, on a strongly coloured red cat, the colouring gets so dark it looks blue or chocolate in places. The blue-grey hue shows up especially on the tail and nose, but this effect usually fades when the cat reaches adulthood. These cats aren't torties, and this colour is being investigated. It may be due to how the pigment is deposited at the extremities when the embryo is developing or it may be an additional mutation that affects the red pigment. Right now it's one of the X-colours and there are some photos further down the page.
MORE CONFUSING COLOURPOINTS
In the section above, the longhair colourpoint tortie clearly has a body paler than the legs, head or tail. Sometimes the contrast is less evident and additional clues are needed to properly work out the colour. Raimi Cyan Rayfield is an example of an more unusual colourpoint. Looking at her adult colours, it is not immediately obvious she is colourpoint because her body is only slightly lighter than her legs, tail and face. At first glance, she appears to be a tortie-and-white with some unusual coffee-coloured areas and blue eyes. Luckily we have some photos of her as a kitten and this gives more clues (Photos and information from Amy Russell, a cat foster parent for a non-kill shelter in Seattle, WA USA)..
As a kitten. she was almost pure white - this rules out mink colouration. She darkened as she grew - this rules in Siamese-type colourpoint. Because she lives in a fairly cool climate (Seattle) she was likely to develop a darker body colour than colourpoints growing up in warmer regions. Her blue eyes reflect red, not green, due to the slightly different eye structure found in colourpoint cats - once more, this means colourpoint. Her tail, and the tails of some of her littermates, have slight kinks near the end - this trait that was once common in Siamese cats. Normally, the black colour is changed to seal (dark brown) on colourpoints, but in Raimi's case it is fully black, fading to dark brown or coffee-brown in some areas only. This is unusual, but not unknown in colourpointed cats that also have the white spotting gene - bicolour pointed (this pattern is familiar in Ragdolls). We know she has the white spotting gene because she has white markings on her paws, face and chest. Adding this up, it makes her a bicolour tortie-point. We can rule out mitted tortie point because she has a white face and chest (mitteds have white chins only).
The formation of the Siamese pattern depends on temperature. That's why Siamese from hot climates have paler bodies and less colour at the points. Siamese from coller climates have more pigment on the points and darker bodies. If an area of the body is shaved e.g. for surgery, that area may grow back darker than ity was before. This is because the bare skin is cooler. This is also why some owners of exhibition colourpointed cats ask their vets to do a midline (abdominal) spay rather than flank-spaying - the flank-spay could cause a darker patch until the next moult. This Thai Bluepoint shows the temperature dependent effect clearly. He suffered an injury to his legs and hind end and needed surgery. Where fur was shaved from his lower back, it has grown back the same colour as the points rather than the same colour as the body. The fur should normally revert to the correct colour following one or two moults.
PERPLEXING SMOKES AND PUZZLING GOLDENS
It can be hard to identify the colour of kittens that inherit the silver gene (Shaded Silver, Chinchilla and Smoke). Many silver colours don't develop fully until the adult coat has grown in. This is particularly true of fluffy-furred smoke kittens. In smokes, the hairshaft closest to the skin is silver. The silver undercoat is most noticeable on the longer, fluffier fur of the body. The actual amount of silver varies from cat to cat; some appear solid colour until the coat is parted, some appear solid colour with a silvery ruff and belly and yet others others appear to have a pointed pattern similar to a Siamese. In general, the shorter fur of the head, limbs and tail will appear darker than the body. Adults that have a high contrast between head, tail, legs and body fur are colloquially termed "masked silvers" though this is not a formally recognised pattern. This can be seen on these 4 random-bred black smoke and blue smoke kittens owned by Kylie Greshik; they have varying degrees of white undercoat and different fur lengths, producing different visual effects!
Not all silvery kittens will stay that way. In the photo, the "masked silver" kitten is due to "fever coat" suppressing the black pigment. Fever coat occurs when the mother runs a temperature during pregnancy and this affects the pigment development in her kittens. This kittens coat will turn its normal colour at the first moult and it may turn out solid black.
While the silver gene gives a silver or greyish undercoat, there is "golden" version that brightens the background colour of tabby cats from the usual greyish or brownish ticked colour to a brighter golden shade by changing the width of the individual colour bands on each hair shaft (known as "wide-band" because the golden bands become wider and there is less room on the hair shaft for the darker bands).
These photos from Lisa Wahl (www.blindcougar.org) show golden tabbies. Some have red markings and others have brown markings, but the background colour is bright golden. The cats came from a breeder who had died, leaving behind a line of golden "Maine Coon type" cats she had developed from barn cats, plus extensive breeding records. Some of the 50 cats rescued have very red undersides, and black paw pads.
To add another confusing type of silver-tabby-that-isn't-really-silver, there is the Bengal "charcoal" series due to a gene inherited from Asian leopard Cats. Charcoals resemble silver tabbies, but have white "goggles" around the eyes and a dark "cape" on their back. So far this is only found in the Bengal and Savannah breeds. Charcoal Savannahs don't have the pronounced mask and cape, but they have the same background colour. Genes imported from wild species interact with the domestic cat's genes to produce new colours and patterns.
SPECIAL EFFECTS - TEXTURE AND LIGHTING
The texture of the fur can add to the difficulty of identifying colours. As well as the wide-band gene, the Tennessee Rex (bred by Frank Whittenburg) has curly fur and the satin gene which gives a mother-of-pearl effect and modifies how the colour appears. The cat in the photo is a black/red tortoiseshell-tabby with the golden gene (tortoiseshell golden). The black areas are brown tabby with black markings. The red areas are red on cream. The breed has the wide-banding gene which affects the ticking of the individual hairs: this gives additional golden tones and golden-tipped blueish tones to black areas. The curly fur makes the undercoat more visible which further disrupts the coat pattern resulting in a multicoloured coat. The golden gene is carried by some cats with the silver gene (in this case the cat's mother was silver tortie-tabby-and-white and the father was a red golden).
The marble pattern Bengal can sometimes have an embossed coat where the darker parts of the tabby coat are raised above the remainder. This is known as the "embossed pattern" among Bengal cat breeders. It occurs on the dorsal stripes, towardsthe tail, where the central stripe is pale with a few wispy black hairs. Either side of this pale central area there is a thick dark stripe with noticeably longer fur.
Some colours are simply unexpected in random bred cats as they involve recessive genes. There's an example near the top of the page showing a chocolate smoke kitten. Anastasia Thormahlen sent me this photo of Jaylin and Jamie. They are female mackerel tabby kittens from a litter of five kittens at Abandoned Animal Rescue in Tomball, Texas. Two other kittens were red-and-white and the fifth was white. Jaylin and Jamie appear to be either cinnamon or cinnamon-silver (any undercoat is hard to determine from photos alone), colours found in several pure breeds, but rarely seen in random-bred cats.
The ancestors of the domestic cat were nondescript black/brown striped tabbies. Over the centuries, mutation produced a wide array of colours based on 2 different pigments. Eumelanin gives the blacks, browns and blues while phaeomelanin gives the reds, fawns and creams. A few other genes give further variations on those colours such silvers, colourpoints and solids/selfs. Mutations are still happening and new colours will still appear e.g. the pearlised versions of colours when a satin gene is present. Unexpected colours also turn up due to inbreeding where recessive genes start showing up, but these are genes that have remained hidden for generations rather than new mutations. Crossing domestic cats with wild species can introduce other mutant genes such as "grizzle" (silver-tipped black).
Some colours are still debated, for example the different caramels are considered distinct colours by some, while others argue that they are variations on a single "caramel" colour. Indigo, a dark grey, is not currently considered a distinct colour. The effect of polygenes can cause variations, for example some grey cats (called "blue" by cat fanciers) can be more bluish or more pinkish or lighter or darker than other grey cats, but will still be grey! This raises the question of how distinct should the hue be in order to be considered a separate colour? If different caramels are not visually distinct enough and can only be identified by knowing the colours of parents and grandparents, then are they really colours in their own right?
AMBER & RUSSETDuring the 1990s, some purebred Norwegian Forest Cats in Sweden produced chocolate/lilac and cinnamon/fawn offspring. However, those colours are not found in the purebred Norwegian Forest Cat gene pool. Had the gene pool become polluted by someone, perhaps generations ago, breeding their Norwegian Forest Cat to another breed? Was it a spontaneous mutation? Crossing of those cats with known chocolate and cinnamon colour cats of other breeds ruled out chocolate/lilac and cinnamon/fawn genes. These cats were a totally new colour, peculiar to the Norwegian Forest Cat gene pool and now called Amber and Light Amber. The Amber effect is due to the extension gene (also called red factor) which controls the production of red and black pigment. The dominant version of the gene produces normal black pigment in the coat while the recessive version produces red pigment. The name comes from the effect of black or brown pigment not being extended throughout the whole coat, but being restricted to the skin of the extremities and to the eyes (for example in bay horses).
This Norwegian Forest Cat was bred by Yve Hamilton Bruce from a silver mackerel tabby female (imported from Denmark) and a classic red tabby and white male. The result was 1 silver tabbies and 2 silver tabbies with white. At just over 3 months old, this silver and white tabby male developed a large patch of bright red hair on his back which continued to spread. Eventually the whole fur will become amber. The effect of amber during the colour-change stage depends on the original colour - solid black or blue, bicolour or tabby. The cat pictured is not a typical amber as it has the silver gene so the amber effect is overlaid on silver.
Similar to amber is russet, which turned up in a line of seal (brown) European-style Burmese in New Zealand in 2007. It has subsequently occurred found in the related Mandalay (similar to the Asian in Europe) and appears to be a mutation of the extension gene. The first known russet was a pure-bred Burmese called “Molly” in 2007. There is now an experimental programme in NZ to breed Russet Burmese and to investigate dilute russet, russet tabby and solid russet (as opposed to the Burmese sepia form of russet).
The first russet kitten “Molly” was born an "odd-coloured lilac (lavender)" which gradually lightened as she grew, progressing through lilac-caramel and chocolate ticked tabby and then dramatically changing to red. Chocolate ticked tabby and red were both impossible from her pedigree, and in any case, reds are not born as chocolate tabbies! Several more unusually coloured kittens were born in different litters and all went through the same colour/pattern changes. The ancestors of these kittens were seal Burmese and had no silver, tabby or Mandalay (Asian) blood. The pedigree had both dilute and chocolate, there were no reds, creams or torties until 4 generations back. DNA testing showed some kittens to be genetically seal and other genetically chocolate. Hence the new colour is due to a different mutation currently known as russet. Russet appears to be due to a recessive mutation that causes black pigment (eumelanin) to gradually fade to a minimal amount while leaving red pigment (phaeomelanin)unaffected.
Russet kittens resemble tabbies at birth, but have pink noses and paw-pads, pale fur around the pads and genitalia and a pale tail-tip - all of which would be dark in tabbies. The muzzle and fur around the eye is ivory. The back is solidly dark rather than ticked, becoming pale ivory halfway down the flanks. The back becomes more ticked appearance, almost a saddle, as kittens undergo the colour change and the face becomes reddish. By age two, they may resemble a red Burmese. It differs from amber as ambers have dark noses and paw-pads. Non-agouti (solid) amber kittens are very dark with a dark face that is last to go red while russet kittens have off-white faces (possible due to Burmese sepia gene in the mix), which are the first part to go red (rather than the last as in ambers), and pale undersides. The russet colour change appears to be slower than the amber colour change. Russet kittens to date have been larger at birth than their siblings and somewhat on the large side as adults.
RED-ON-BLUE TABBIES & PSEUDO-CINNAMON
Colours are also modified by numerous genes (known as polygenes) which creates warmer or cooler tones. Marjan Boonen, a breeder in The Netherlands, has noticed that red cats sometimes have a bluish hue on their extremities: tail, feet, muzzles and ears. In many cases, kittens with bluish extremities turned fully red as they grew older, but some adult cats still retain the blue/grey hue. Tosca, a solid red female shows really clear bluish hues while the red-and-white bicolour housecat shows the blue tailtip really well and the lighter part of his tabby pattern also looks a bit grey. In black/brown tabby cats, polygenes are known to affect the background colour, sometimes warming (brightening) it and sometimes "cooling" it. In silver cats, there is sometimes a golden "tarnish" on the muzzle. In red or cream cats (the red/cream colour is due to phaeomelanin) the bluish effect may be due to such genes causing some eumelanin to be expressed. Because the bluish hue is retricted to the extremities (points) it may be affected by temperature, as those regions are cooler than the cat's torso.
Here are some photos of an unusually coloured 11-month-old household pet called Oliver (owned by Jill Bristow) shown in ACFA in Canada in 2015. He started off as a dark orange tabby feral/stray kitten caught in a squirrel trap when he was about six weeks old in Winnipeg. He then darkened as he has got older and to a deeper orange brown colour which has a slight bluish undertone. It definitely looks much more brown than a normal red tabby and resembles the cinnamon colour (a recessive allele of Black i.e. a eumelanin colour). Howeve Oliver DNA tests as B/B and non-agouti meaning he should be self black (if no O gene is present) or self red (if the O gene is also present). As he is not black, he must be genetically red. He is not chocolate or cinnamon (alleles of black), despite the visual appearance. It's as though the red gene doesn't fully suppress the expression of eumelanin. He carries colourpoint and blue dilution. Non-agouti red usually shows ghost markings, but not on a blue background. The blue undertone is the unknown factor that might be a novel mutation tht modifies the base colour of red.
SALT AND PEPPER, TWEED AND SPECKLES
Salt-and-pepper colours include various unidentified "one-off mutations" as well as cats with the condition vitiligo that causes fur to turn white during their lifetimes. For details and images of vitiligo/leukotrichia, see Feline Depigmentation Conditions - Vitiligo, Leukotrichia, Leukoderma.
Left: Pandora (owned by Bill B, Granby, MA, USA) should have turned out a red/black brindled tortie. For some reason, probably a mutant gene, she didn't produce red pigment; the hair that should have been red ended up white giving a black/white brindle effect. A red/white brindle has also been seen; in that case it was the black colour that wasn't produced. These really are X-colours! The black/white brindle was spayed and the red/white brindle was feral, so it's not known if the colour could be inherited to produce a roan cat (in roan, the colour hairs and white hairs should be evenly mixed). In fact "tweed" is a recently noted colour mutation similar to roan in horses where white hairs are evenly intermixed with the solid base colour, such as black, to give a salt and pepper effect. Some ancient descriptions of Thai cat varieties mention a "Saem Sawet" which is a black cat with white speckles. Until now, many of these Thai descriptions were thought to be mythical, but some are turning out to be poetic descriptions of colours that are only now being rediscovered.
Right: A "tweed" kitten found by Claire Jones in Surrey, England. Claire runs a rehoming cattery and took in the tweed kitten for rehoming. "Tweed" or "roan" has only recently been noticed by the modern cat fancy and is not yet a recognised colour. In the Lykoi breed, TICA currently defines this colour/pattern as black evenly interspersed with amelanistic hairs. In theory, any solid colour could have a roan/tweed version and TICA have been asked to add "roan" to their list of definitions as being evenly mixed colour and white hairs; the coloured hairs define the type of roan e.g. red roan, blue roan, black roan.
There are more details of roan/tweed and similar colours on Roan, Tweed and "Salt and Pepper" Colours. One particular salt-and-pepper effect, often with white rimmed ears, is found in Poland and Romania and is being selectively bred. Salt and pepper is different from roan because the legs, tail and face look pale grey or nearly white while the body has fewer white hairs and looks coloured (the cats can have any colour or pattern peppered with white hairs). Distinguishing characteristics of salt and Pepper cats are the white rims on their ears and the "reverse colourpoint" pattern.
Now we come to speckles! Keeley Rochelle Pilling ( Northernpaws) provided these photos of her cat Tedde who has dark speckles on his legs and feet. These were present right from birth and appear to be a mutation where the underlying colour breaks through th white masking. It is unusual to see so much speckling and on all of the limbs.
Then in 2014, Al in Michigan sent me photos of his cat, Jasmine, who also has dark speckles on her legs and feet and very well speckled limbs. Jasmine died in January 2012. All tells me she was a docile, affectionate, soft-spoken little thing who weighed less than five pounds andwho loved to be brushed. She was a black-and-white "tuxedo" pattern cat, but one with black polka-dots all over her white gloves and socks. Not visible in these images, she also had a black dot in the center of her chest in the place where some cats have a white dot, and a cluster of several black polka-dots on her white belly. Her ancestry is unknown. She was found on the street as a tiny kitten, taken in and hand-fed and hand-raised by a neighbor in 1997 or 1998.
THE CHIMERA CONUNDRUM
In Japan, there was a "tortie" male whose coat was a mix of black, grey and white patches. Ignoring the white, which is simply due to a white spotting gene, this is genetically impossible because black is non-dilute and blue is dilute and a cat cannot be both dilute and non-dilute at the same time! This cat, Panda, sired many kittens. The mystery was solved years later when a male red, blue and white Maine Coon tortie, also fertile, was born. Again leaving aside the white spotting, because red is non-dilute and blue is dilute, Pretty Boy Floid was impossible according to normal genetics. The answer was the he was a chimera – two fertilised eggs had become fused in the womb. One had the red colour and one had the blue colour. Pretty Boy Floid was really two cats rolled into one! Although Panda was long gone by this time, it is probably that he was also two cats rolled into one.
Since then, a few other chimeras have been identified where the cat is an impossible mixture of colours. To properly identify a cat as a chimera, genetic tests are needed, so any cat with an impossible mix of colours (once everything else has been ruled out) can only be a "possible chimera". Grace. below, has a coat that is a mix of black, grey and white patches; the black and grey are not arranged in a tabby pattern. One front paw has a black spot on one side and a grey spot on the other. her owner, Roshelle Conner describes it as "when she is sitting, from the side, it almost looks like she has a long gown with a hoop skirt under it, and layers of lace (brindling), on the dress!"
GREEN AND PINK CATS
Some X-colours are due to environmental effects rather than genetics. The famous greenish kitten called "Miss Greeny" born in north-west Denmark in 1995, didn't stay green. The unusual colour turned out to be copper residue on the fur due to copper-contaminated water. When removed from the source of copper (which could eventually have killed her) Miss Greeny lost the green patina and grew up grey. The online article about the genetics of green and olive cats (green tabbies, green torties etc) is an April Fools Joke.
A crimson-and-white cat reported in Britain was also due to contamination. A white cat returned from a daily stroll with bright pink markings. The source of contamination wasn't identified, but was ascertained to be non-toxic – possibly the cat had rolled in a dye used to mark sheep or a pink paintball pellet.
THE HOAX COLOURS
Image editing software has allowed people to create pictures of unusual colours and patterns that are not found in real life e.g. tiger or Dalmation dog markings on a domestic cat. Even so, they fool some people who are unfamiliar with cat colours; from time to time I get queries asking what the colour or breed is and where to get one. Most are obvious jokes e.g. images from a book called "Why Paint Cats" though others do the rounds of email and blogs and are less obvious.
This widely circulated image appears to be of Birman-type or Ragdoll-type kittens with the body colour changed from the normal cream colour to a bright ginger. It is genetically impossible to have such dark points colourpoints on this body colour. The colourpoint gene, is a form of temperature-dependent albinism and always produce a pale body while restricting the full colour regions to the points (face, legs and tail) resulting in the "Siamese" pattern. Being temperature dependent, the amount of colour also depends on the environmental temperature. Secondly, if the kittens had the gene for a red colour this would produce tortoiseshell points on a pale (creamy) body or red points on a pale cream body, not dark points on a red body. Show-quality Birmans do not have white facial markings while bicolour Ragdolls do. There is a video of one such kitten (Marigold) from a pet market at Beijing, China, which indicates the kitten was probably bleached or dyed to resemble a more exotic animal, such as a red panda. Dyeing dogs - and now possibly cats - seems to be a common practice in urban China where chows painted to resemble giant pandas have been photographed with surprising regularity!
WHAT COLOUR IS MY CAT – A PROCESS OF ELIMINATION
First look at the pattern, disregarding any white patches and making sure you know the difference between classic tabby pattern and tortie pattern (a common mistake). Most of the queries I get relate to different types of tortie cat.
Is there a tabby pattern? Is the pattern overlaid on patches of different colours such as black/brown and red? If so, you have a tabby-tortie (torbie).
Is the background silvery or is it a paler version of the marking colour? That gives you the difference between a silver tabby/tortie/torbie and an ordinary tabby/tortie/torbie.
Are the legs, head and tail much darker than the body? That tells you if there is colourpoint in the mix. Mink will produce moderately darker legs, head and tail while sepia produces only slightly darker legs, head and tail. Again, you might also have silver in there, giving a silvery background colour.
Is the cat a mix of impossible colours e.g. patches of grey and patches of black (don't confuse these with black markings on a silver tabby) or patches of orange-red with patches of grey? A mix of patches of dilute colour and non-dilute colour suggests a chimera.
Caramels and Ambers are best left to judges and breeders and usually require the cat's pedigree in order to work out what is going on.
If your cat still doesn't conform to any of the colours and patterns described, it might well be an oddity (or if it's a photo you've been sent, it might be a hoax or joke).