Sable rats are very similar in colour to sable Burmese cats (aka brown Burmese cats in the UK). They are a rich, deep colour which is substantially different to the other various varieties of brown rat.
As with Burmese, many sables have a cold and silvered colour to them, which isn’t correct. It isn’t the easiest variety to breed, as mating to standard Burmese (which are selected to be pale) can give a too-pale overall colour to sables. The best outcross is black, but due to the sable colour being made up of two separate recessive genes you will only end up with a few sables when breeding the offspring of black x sable back to sable, as you will also get some too-dark Burmese in the mix too.
Genetics: Non-agouti with two copies of the Burmese gene and two copies of the Himalayan gene (aaBebuBebuchch)
NFRS standard: To be a warm dark otter brown with subtle darker points on the feet, tail, face, and ears. Devoid of dinginess, silvering, or patches. Contrast between points and body colour not to be overstated. Any suggestion of black in the points to be penalised. Eyes black.