Dominant black

Dominant black, usually known simply as black, is a very common colour in the dog world. It is able to mask many other colours. In order to get a black dog, the dog needs at least one copy of E or Em the E-locus (allows eumelanin in the coat), at least one copy of B on the B-locus (gives black eumelanin rather than liver) and at least one copy of K (or Kbr) on the K-locus which overrides the agouti pattern on the A-locus. As all three of those genes are dominant on their locii and common, it is not surprising that many crossbreeds and breeds in general come in black.

Genetically, a black dog is a black dog is a black dog. Having said that, it is not uncommon for part of the coat to be sunburnt and ligthen to a brown shade. This should not be confused with liver. A dog can never be black and liver at the same time. This sort of brown cast to the coat is often called bronzing or sunburning.

Certain dogs, such as poodles, can sometimes have their black coat fade somewhat with age. In poodles this is considered undesirable, though it does not affect the dog besides its colour. The genetics causing this is unknown - it could possibly have to do with the coat structure itself, though this does not explain how some poodles stay dark black and others don't.

A black labrador retriever