If you’ve ever heard a pet rat breeder talk about Himalayan, Burmese, and English Irish, you may be thoroughly confused.
Did you know that fancy rats do not only come in seven varieties, but also in tons of different colors?
The American Fancy Rat and Mouse Association recognizes over 40 colors across 6 sections, as well as different markings1.
This article will give you a rundown of all the recognized colors and markings that can be found in pet rats.
6 Fancy Rat Sections by Color & Body Markings
1. Self Rats
So-called “self” rats have a color that is even throughout their entire body, including the skin, feet, tail and ears2.
The most common self rat is the black rat, which has an evenly black coat, as the name suggests, and black eyes.
Black Rat
Another popular self rat color is blue. Blue rats have a slate blue coat, and black or dark ruby eyes. Similar to the blue rat is the Russian blue rat, which is a little darker3.
Lighter-colored self rats are the beige rat, which has ruby eyes, the champagne rat with red eyes, and the lilac and mink rats, which have coats of different shades of grey4. The chocolate and cocoa self rats are two different shades of a rich, chocolatey brown color.
Champagne Rat
Some rarer self rats include blue-beige, platinum, pink-eyed platinum, powder blue, Russian dove, and sky blue2.
Powder Blue
The pink-eyed white rat, which is more commonly referred to as albino, is also a self rat.
Another remarkable self rat is the black-eyed white rat, which is completely white (like an albino rat) but has black eyes.
2. Any Other Color Rats
The “Any other color” (AOC) section includes rat colors that are mostly genetically based on the color agouti5.
Agouti is pretty much the “standard” rat color that also occurs in wild Norway rats. It looks like a regular brown-grey color, but upon closer inspection, you may notice that there are some black guard hairs, as well as a more silvery color on the belly.
What makes the agouti coat special is that each individual hair actually has different shades of pigmentation, usually darker at the base and lighter at the tip6.
If you blow on an agouti rat’s fur and the hairs separate, you can see these “rings” of different pigmentation. The overall effect is a salt-and-pepper type of appearance, depending on how the light hits the fur.
Cinnamon
There are different variations of the agouti color5: blue agouti (a cross between a blue and an agouti rat), cinnamon (a cross between an agouti and a mink rat), or cinnamon pearl (agouti + mink + pearl, genetically speaking).
Others include the chinchilla color (with a silvery grey appearance), fawn (a rich orange color, and dark ruby eyes), lynx and pearl (variations of grey agouti), and Russian blue agouti (agouti + Russian blue).
Russian Blue Agouti
3. Any Other Color Pattern Rats
“Any other color pattern” (AOCP) rats have a combination of two or more colors – other than white – in a specific, recognized pattern7.
This section includes mainly variations of Burmese and Siamese rats, which have a base color and then different “points” of a darker color. These points are usually found on the nose, ears, paws, and the base of the tail.
Himalayan Rat
Different shades include the B.E. Siamese, the Blue Point Siamese, the Russian Blue Point and Russian Blue Agouti Siamese, the Seal Point Siamese, the Himalayan, and the Burmese rat7,8.
Siamese Rat
A special type of AOCP rat is the Merle rat, which can be of any color and is characterized by distinct darker splash-spots on its whole body.
Pearl Merle Rat
4. Silvered Rats
The “silvered” color section is populated by rats of different shades of silver. Their coat is evenly speckled with white hairs. Depending on the base color, silvered rats can be amber rats, silver black, silver blue, silver chocolate, silver fawn, silver lilac, or silver mink.
5. Marked Rats
Marked rats have markings on their coat9. The most popular marked rat is probably the hooded rat.
Hooded rats have white sides, legs, and feet. Their “hood” can come in any color and covers the head, neck, and shoulders. From the hood, a spine marking runs down the spine in a straight line to the base of the tail10.
Hooded Rat
Variegated rats are very similar to hooded rats, but instead of a spine marking, they have flecks of color on their back.
Variegated Rat
Bareback rats also look like hooded rats, but they lack the spine marking altogether11. When the marking on the rat is smaller than a hood, and only covers the head, that’s called a capped rat.
Capped Rat
Masked rats have a marking that only covers their face (around the eyes and above the nose).
Masked Rat
The Down Under rat, which first appeared in Australia, has a belly stripe on a coat of any color. Down Unders are considered a variation of hooded rats, and can still display a hooded, variegated or capped marking in addition to the belly markings12.
Down Under Rat
Rats with a completely white belly and any darker top color are Berkshire rats. When the white belly marking is small and accompanied by white feet and a white tail tip, this is called Irish. English Irish rats, on the other hand, have a small white triangle on the underside of their chest.
Blazed rats have a white, wedge-shaped blaze running from their muzzle to a point between their ears. Dalmatian rats have a white base color, which is covered in numerous spots of any recognized color.
Interestingly, there is some evidence to suggest that rats with extensive white markings may be friendlier and more likely to seek human interaction.
Blazed Rat
6. Odd-Eye Rats
Odd-eye rats have two differently colored eyes, as the name suggests. Usually, one eye is pink and the other is either black or a dark ruby color13,14. The coat may be of any recognized color or marking.
Often, odd-eye rats are capped, and the most common colors are fawn or beige (less frequently cinnamon or lilac).
Odd-Eye Rats
Other, Non-Recognized Colors
Of course, this list of colors and markings is not definitive. There are a myriad of colors and markings that is not (yet) standardized or recognized at official fancy rat shows, but that are bred and sold worldwide.
Some of these are very striking, such as the apricot rat or the chocolate agouti15. They are too numerous to be listed here, and surely there will be many new variations appearing in the future!
Rat Color Genetics
How is it possible that rats can have all these different colors and markings, you might wonder? How did we end up with these variations, and why are there sometimes new ones popping up?
Dominant & Recessive Genes
Rat color and coat type genetics can be complicated. As you might know, every gene is actually present in two variations in an individual rat, one variation (allele) coming from the mother, the other from the father.
Both of these alleles might be the same – they might both be for the color black, for example. But in case that they are different, the color of the rat is determined by which of these traits is dominant. The agouti gene is dominant, meaning that a rat only needs to have one agouti allele to show the agouti banding on their hairs. The albino gene is recessive, so there must be two albino alleles present (from both the mother and the father) for the rat to be albino.
| Parent 1 | Parent 2 | Offspring Color |
|---|---|---|
| Agouti allele | Albino allele | Agouti |
| Albino allele | Albino allele | Albino |
So far, so good – but how do all the other colors and marking come into play?
They are defined by the brown locus, the agouti locus, and by the effect of modifier genes on these base color genes16.
Loci & Modifier Genes
The agouti locus determines whether the rat will have an agouti coat (different pigmentation bands on the same hairs) or a self coat (evenly colored hairs). The brown locus determines whether the color pigment is brown or black.
Modifier genes can also be dominant or recessive. They are found on the dilute locus, the albino locus and the grey locus and they influence the appearance of the base color.
Markings and shadings can also be influenced by dominant or recessive genes, and often they will change when the rat ages. Ageing black rats will get grey or rusty brown patches, and hooded rats often start losing the hooded marking as they grow older.
To make matters even more complicated, some genetic traits will cover up other genes. An albino rat is always white, but it still carries the genetic information for other colors and markings and can pass these on to its pups.
Most albino rats nowadays are actually hooded rats, and therefore you might see many hooded markings in their offspring, unless you pair them with another albino rat.
Cute in Any Color!
We hope that this brief introduction to rat genetics helped you understand the many colors and patterns that they come in.
Rest assured that all rats are very cute and worthy of love – and no matter the color, they make great pets!
Related: 7 Types of Pet Rats: Domestic Rat Varieties Explored
Resources:
1. American Fancy Rat & Mouse Association. Rat Standards 2018. https://www.afrma.org/fancyrm.htm.
2. American Fancy Rat & Mouse Association. Self 2020. https://www.afrma.org/ratselfs.htm.
3. Roberts E. A Blue Mutation in the Rat Science 1929;70:334-334. https://www.science.org/doi/abs/10.1126/science.70.1814.334.
4. Robinson R. Mink and Pearl: New Color Mutants in the Norway Rat. Journal of Heredity 1994;85:142-143. https://doi.org/10.1093/oxfordjournals.jhered.a111414.
5. American Fancy Rat & Mouse Association. AOC 2020. https://www.afrma.org/rataoc.htm.
6. Siracusa LD. The agouti gene: turned on to yellow. Trends Genet 1994;10:423-428. https://pubmed.ncbi.nlm.nih.gov/7871591/.
7. American Fancy Rat & Mouse Association. AOCP 2018. https://www.afrma.org/rataocp.htm.
8. MOUTIER R, TOYAMA K, CHARRIER MF. Himalayan allele at the albino locus in the Norway rat. Journal of Heredity 1973;64:303-304. https://doi.org/10.1093/oxfordjournals.jhered.a108421.
9. American Fancy Rat & Mouse Association. Marked 2021. https://www.afrma.org/ratmkd.htm.
10. Kuramoto T, Nakanishi S, Ochiai M, et al. Origins of Albino and Hooded Rats: Implications from Molecular Genetic Analysis across Modern Laboratory Rat Strains. PLOS ONE 2012;7:e43059. https://doi.org/10.1371/journal.pone.0043059.
11. Stolc V. Linkage of hooded and hood-modifier genes in the rat. Journal of Heredity 1984;75:81-81. https://doi.org/10.1093/oxfordjournals.jhered.a109877.
12. Perez C. Unique dominant rat spotting gene known as australian downunder may represent a new major spotting gene of rattus norvegicus. Pigment Cell Research 2004;17:451-451. https://www.ingentaconnect.com/content/mksg/pcr/2004/00000017/00000004/art00092.
13. American Fancy Rat & Mouse Association. Odd-eye 2018. https://www.afrma.org/ratsoe.htm.
14. Gumbreck LG, Stanley AJ, Allison JE, et al. Restriction of color in the rat with associated sterility in the male and heterochromia in both sexes. Journal of Experimental Zoology 1972;180:333-349. https://doi.org/10.1002/jez.1401800305.
15. American Fancy Rat & Mouse Association. Non-recognized markings, colors and coats 2020.
16. American Fancy Rat & Mouse Association. Rat Genetics, part 1. 1996. https://www.afrma.org/ratgenpart1.htm.
Nina has a degree from the Veterinary School in Zurich, with a special focus on microbiological research. Nina has a passion for sports, nutrition and the outdoors and she loves all pets, but rats have a special place in her heart. When she’s not working or reading and writing about all things related to pet health, she loves to travel and surf.
As a small animal veterinarian, Nina is your go-to expert on pet health and nutrition.
