The secret charm of Russian blacks

The Black Side of Russian Blue Charm

What do you think of Russian cats in black? Most people know the Russian Blue, but not everyone knows that the very same breed also comes in black and white. In Finland, Russian Blacks can be found exclusively in our cattery. They are fully pedigreed cats, identical to the classic “blues” in every way, except for one single gene: the dilution gene.

The secret behind the colour
The Russian Blue’s famous silvery sheen is created by a recessive dilution gene (d), which affects how pigment granules are distributed within each hair. In a black coat, pigment granules are separated and evenly spread out, giving the fur a rich, glossy look. The dilution gene, however, causes the granules to clump together and distribute unevenly — making the colour appear lighter and turning black into that soft blue tone. This is nicely illustrated by a simplified diagram of pigment granules in cat hair, based on photographs from a microscopic study (source).

Genetically, it looks like this:

• DD or Dd → black coat (full colour)
• dd→ blue coat (diluted black).

If a Russian Black is heterozygous for dilution (Dd), then when paired with a blue cat (dd), the probability of blue kittens is 50%.

If a Russian Black is homozygous for dilution (DD), then when paired with a blue cat (dd), all kittens will be black and heterozygous for dilution (Dd).

Can two Russian Blacks produce blue kittens? The answer is yes — if both cats are heterozygous for dilution (Dd), meaning they carry the hidden d gene. In that case, the probability of blue (dd) kittens is 25%.

Recognition in European cat fancier systems
The Russian breed is officially recognised in three colours by several European and international feline federations:

• WCF – Russian Blue (RUS): blue (a), black (n), white (w)
• LOOF – recognises the same three colours
• GCCF – uses the straightforward naming “Russian”: Russian Blue, Russian Black, Russian White
• FIFe – officially registers only the blue colour, although an expansion of the standard is being discussed
• TICA, CFA – North American systems that are active in Europe recognise only the blue variety

Under WCF rules, we formally say “Russian Blue in black colour”, which often raises questions. GCCF terminology sounds more natural — Russian Blue, Russian Black, Russian White, highlighting that all three colours belong to one elegant breed.