The Russian Blue cat, commonly referred to as just Russian Blue, is a cat breed with colors that vary from a light shimmering silver to a darker, slate grey. The short, dense coat, which stands out from the body, has been the breed's hallmark for more than a century.

The Havana Brown was the result of a planned breeding between Siamese and domestic black cats, by a group of cat fanciers in England, in the 1950s. Early breeders introduced a Siamese type Russian Blue into their breeding. However, using current genetic testing, it is believed that almost none remain in the gene pool.