Russian Blue vs the Other Grey Cats: The Registries' Own Tells
Four grey cats the internet confuses, separated by the registries' own words: coat structure, eye color rules, and one pair of standards that disqualify each other's eyes.
Published August 21, 2026 4 min read
Contents
Four solid grey breeds share the internet's photos and none of the registries' definitions. Here is each pairing separated by the documents, never by vibes. (The one grey breed genuinely RELATED to the Russian Blue, the longhaired Nebelung, has its own page.)
Russian Blue vs British Blue: a color name, not a sister breed
"British Blue" is not a second Russian breed. It is the British Shorthair's most famous COLOUR, per 's own history text. The registries never pair the two: 's Similar Breeds field, a template slot on every breed page, is empty for the Russian Blue and does not name it on the British Shorthair's page either. The cats separate in one hand-stroke. CFA's Russian Blue standard requires a DOUBLE coat standing away from the body, while its British Shorthair standard reads "not double coated or woolly." Build finishes it: fine-boned and foreign against cobby and massive, green eyes against copper-to-gold.
Russian Blue vs Chartreux: the mutual disqualification
The sharpest registry fact in this file: these two breeds' standards disqualify EACH OTHER'S eye color. Green is required for the Russian Blue and disqualifying for the Chartreux (copper-to-gold required). No other pair we have profiled carries an absolute two-way eye rule. The builds read as opposites in the standards' own words: "foreign, fine boned" against "husky, robust, neither cobby nor classic." One market note for Australian readers: 's own material states the Chartreux has "no exhibits presently in Australia" (a 2020-dated statement). A "Chartreux" listing there deserves double scrutiny.
Russian Blue vs Korat: double coat against the fancy's only true single
The Korat is the closest visual double: another naturally-occurring, locked-to-one-color silver-blue breed. The coat settles it. The Korat is the only breed in this whole comparison set where every registry uses the literal word SINGLE for the coat, against the Russian Blue's every-registry double coat. Flat, close-lying sheen means Korat; plush, stand-away density means Russian Blue.
The face helps too (the Korat's heart-shaped head against the Russian's smiling wedge). And the Korat's own registry carries this file's most useful sentence: 's Korat page states outright that its low-shedding coat does NOT make it hypoallergenic. That is the plainest registry debunk of the claim that follows every grey breed (our hypoallergenic page does the Russian Blue's version).
The one-glance table
Coat: double and standing away (Russian Blue), not-double (British Blue), woolly-thick (Chartreux), single and close (Korat). Eyes: green required (Russian Blue, adult), copper-gold (British Blue and Chartreux), peridot green (Korat). Build: fine-boned foreign, cobby, husky-robust, semi-cobby. A grey cat in a shelter matches whichever column it matches, and most match none: the mix page explains why most grey cats are simply grey cats.
Four grey cats on one card
| Coat | Eyes | Build | |
|---|---|---|---|
| Russian Blue | DOUBLE, stands away, silver-tipped | Green, required | Fine-boned, foreign |
| British Blue (BSH) | Explicitly NOT double | Copper to gold | Cobby, massive |
| Chartreux | Woolly, thick | Copper-gold (green disqualifies) | Husky, robust |
| Korat | SINGLE (every registry's own word) | Peridot green | Semi-cobby, heart-shaped face |
The vet's take
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Frequently asked questions
What is the difference between a Russian Blue and a British Blue?
A breed versus a color: British Blue is the British Shorthair's signature color. The coats separate them in one stroke: double and standing away (Russian) against explicitly not-double (British), and green eyes against copper.
Russian Blue or Chartreux: how do I tell?
The eyes end the argument: green is REQUIRED for a Russian Blue and DISQUALIFYING for a Chartreux, in both standards' own words. The Chartreux is also a visibly heavier, huskier cat.
Is a Korat the same as a Russian Blue?
No: the Korat wears the only true single coat in this comparison set (every registry's own word), against the Russian Blue's universal double coat, and a heart-shaped face against the Russian wedge.
Are any of these breeds related to the Russian Blue?
Not these three: the registries draw no family lines here. The one formally related breed is the longhaired Nebelung, whose rules allow Russian Blue ancestry by name: it has its own page.
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This is information, not veterinary advice, and it cannot tell you what is wrong with your cat. Our rule is a simple one: if something is wrong with your cat, call your vet, and call an emergency clinic if it is out of hours. Nothing you read here is a reason to wait.
Medical information applies to every reader. Prices, legal duties and common practice do not: unless stated otherwise, they are given for the United States, and they differ in the UK, Canada and Australia, and often between states or provinces. Check with your own vet and your own local authority.
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