Coat colour DNA test – dilute (D-locus, d1 variant)

The dilute (D-locus, d1 variant) DNA test can be used by breeders and owners to screen their dogs to see if they carry this gene variant linked to dilute coat colour 

Details about the test

A number of different gene variants have been discovered that change a dog’s natural pigmentation. This particular colour-changing variant (known as d1) may affect the colouring of a dog’s hair, eyes and skin, including their nose, making them paler than expected (dilute).

At the moment, we only record this coat colour DNA test for Labrador Retrievers.

Coat colour changes

This gene variant dilutes a dog’s natural colouring, e.g., black Labradors with this variant tend to have an off or dull black or dark grey coat colour (known as ‘charcoal’), chocolate Labradors tend to have a silver-coloured coat (known as ‘silver’) and yellow Labradors have a coat colour known as ‘champagne’. The effect of the dilute gene variant on yellow Labrador’s coat colour may vary but the changes are very subtle and may be easily confused with non-dilute yellows. Dogs with dilute coat colours tend to have lighter-coloured eyes and noses.

These three colours (charcoal, silver and champagne) are non-breed standard colours, i.e., they are not accepted in the Labrador’s breed standard.


This coat colour-changing variant is inherited in an autosomal-recessive way. This means that a dog must have two copies of this colour-changing variant (one inherited from their mother and one inherited from their father) before its coat colour is affected. Dogs that only inherit one copy of the gene variant (from either their mother or their father) will not be affected, but will be a carrier and may pass the gene on to any offspring.

Which laboratories test for this trait?

A quick internet search will help you identify laboratories that run this DNA test. If you would like us to record this test result on our database, please ensure that the laboratory you choose is on our list of accepted laboratories. Please note that we currently only record results for this colour-coat DNA test for Labrador Retrievers.

Any DNA test result submitted to us must have at least two forms of identification on the result certificate. This must include the dog’s microchip or tattoo number, along with either the dog’s registered name or registered number. Test results that don’t carry these identifying features can’t be accepted. You can send in your DNA test results to

Health results (The Kennel Club)



How are results recorded?

Dogs that have been tested for this genetic variant can be described as either: clear, carrier or dilute.


These dogs are unlikely to have a dilute coat linked to the gene variant that has been tested for.

If your dog is clear, they don’t have any copies of the gene colour-diluting gene variant that has been tested for and will only pass on a normal copy of the gene to any offspring.


These dogs are unlikely to have a dilute coat linked to the gene variant that has been tested for.

Carriers have one gene variant linked to dilute colours (that they inherited from either their mother or their father). Two copies of the dilute variant are needed to affect a dog’s coat colour, which means that dogs with only one copy are unlikely to be affected. When bred from, a carrier has a 50 per cent chance of passing the colour-diluting gene variant on to their puppies.


These dogs are likely to have a dilute coat colour.

These dogs have two copies of the colour-diluting gene variant (inherited from both their mother and their father). If bred from, this dog will pass on a copy of this gene variant to their puppies so that all puppies will be at least carriers, but remember that two copies are needed to affect the coat colour of a dog.

How to find other dogs that are clear for this dilute gene variant

Please check our PDF of dogs that have tested clear for the dilute gene and whose results have been sent to us. Our list is updated monthly and will only include dogs that are clear.