Pigment Types

So you want to learn about dog coat colors?

The first is to understand that dogs have two types of pigment.

Pigment is what gives a dog its unique coat color.

But it also affects its eye color, the nose color, and the skin pigment of our dogs.

And the distribution of pigment types in the coat determines a dog’s pattern.

Dogs have two types of melanin:

eumelanin
phaeomelanin

Both of these pigments have a “default” colour.

Eumelanin is black. Phaeomelanin is yellow-red.

But different genetic traits can modify the color of each pigment.

Eumelanin

Eumelanin is a black pigment.

Some genes can modify the color of eumelanin from black to other colors:

The B locus controls, if the dog has the building plan for normal black eumelanin. If he lacks this information he can only produce brown eumelanin. note: Whenever we talk about “brown” in terms of color genetics, we only ever mean a chocolate or liver color (like on a brown Labrador).
The D locus helps to distribute the pigment evenly in the hair. If this information is missing, the pigment will clump together and appear “diluted“. Diluted black is called blue, diluted brown is lilac.

Eumelanin can be black or brown (chocolate) or blue (gray) or lilac (light dusty taupe).

All of the following dogs are solid dark. One for each possible base color of eumelanin:

This is a black dog:

This is a blue dog with a diluted black color:

This is a brown dog with a chocolate color:

This is a lilac dog with a diluted brown color:

But eumelanin does not only dye all or some of your dog’s coat a certain color.

It is also the pigment type that we see in a dog’s eye color or nose pigment.

Every dog can only have one eumelanin base color.

Body parts that get their color from eumelanin are always either black or brown or blue or lilac.

A dog with a black-based pattern has a black nose.
A dog with a brown-based pattern has a chocolate brown nose.
A dog with a blue-based pattern has a slate gray nose.
A dog with a lilac-based pattern has a diluted brown nose.

Since all the eumelanin on the same dog has the same color, you will never find a black-based pattern with a nose color other than black. Or a brown-based pattern with a nose color other than brown.

All of these dogs are solid dark. Look at their nose colors.

coatsandcolors Pigment Types Dogs Black Nose Pigment

coatsandcolors Pigment Types Dogs Blue Nose Pigment

Eumelanin base color affects brindle striping, masks, dark sabling, hair banding, dark saddles, or any other dark markings a dog might have.

We often describe a dog’s coat color in terms of its eumelanin color. When talking about coat colors, we say things like “black-and-tan“, chocolate merle“, “blue brindle“, “lilac fawn“, etc.

coatsandcolors Pigment Types in Dogs example blue brindle

coatsandcolors Pigment Types in Dogs example brwn tan point

Even if you can’t see any eumelanin in a dog’s coat at all (e.g. in solid yellow or white dogs), you can often determine the eumelanin base color just by looking at the dog’s nose leather.

If the eumelanin color in the coat doesn’t seem to match the eumelanin color of the nose on the same dog, something different might be going on. e.g. graying, merle, seal, domino, etc.

Phaeomelanin

The second type of pigment in our dog’s coats is called phaeomelanin (or pheomelanin).

Phaeomelanin is often called the yellow pigment or red pigment. But this pigment can have any shade from white through blonde or orange to deep red mahogany or chestnut colors.

Here, we don’t have distinct colors like with eumelanin (black, liver, blue, or lilac)

Phaeomelanin provides more of a gradual scale.

Red intensity can come in many different shades.

Sometimes, we can even find different colors of phaeomelanin on the same dog, e.g. darker pigment around the ear rims or countershading with lighter markings on the dog underbody.

coatsandcolors Pigment Types Dogs Phaeomelanin Countershading

coatsandcolors Pigment Types Dogs Phaeomelanin Ear Lacing

White

A lack of pigment in the hair shafts causes the coat to appear white.

White is not a color. White is the absence of pigment.

And very many dogs show at least a partial lack of pigmentation.

The missing pigment can, in some cases, extend to the skin and eye color. For example, it can cause pink eye rims, pink patches on the nose (we call this a butterfly nose), or blue eyes.

Dogs with a lot of white on the head are also at risk for hearing impairment.

But not every white dog truly lacks pigmentation!

As you just learned, phaeomelanin can sometimes have a very, very light intensity. This can make a dog appear white when it’s actually just a very light blonde color.

Many solid white dog breeds like white Poodles, Maltese, Samoyeds, or Westies are actually well-pigmented. Their phaeomelanin just has a very light cream color.

Patterns

Every hair follicle has plenty of pigment cells. They make pigment and transfer it to the growing hairs. All the different patterns are produced by eumelanin or phaeomelanin.

Some dogs only have one type of pigment in their coat.

Some dogs are solid black, blue, brown, or lilac. Their pigment cells only produce eumelanin.

Some dogs are solid red, yellow, or cream. Their pigment cells only produce phaeomelanin.

But of course, many dogs have a coat with both types of pigment.

All the base patterns are controlled by whatever gene variants a dog inherited on its K locus, E locus, and A locus. And their interaction in controlling pigment distribution.

In some patterns, the change from one pigment type to the other follows a spatial pattern with defined edges between the different pigment types, e.g. in brindle, a mask, or black-and-tan.

coatsandcolors Pigment Types in Dogs black and tan pattern

coatsandcolors Pigment Types in Dogs brindle pattern

In some patterns, the switch from one pigment to the other happens in single hairs during hair growth. This leads to hair banding (common in agouti) or hair tipping (common in sable).

coatsandcolors Pigment Types Dogs hair banding 1

coatsandcolors Pigment Types Dogs hair banding 2

Noteworthy: Many breeds use “breed terms” for different patterns that can get quite odd or imaginative, like phantom (Poodle term for tan points) or dapple (Dachshund term for merle).

These breed-specific terms for coat colors can be a little puzzling for beginners. Please remember that traditional names for some colors are rarely based on coat color genetics.

I know this can be confusing at first. But understanding the types of pigment and their effect on a dog’s color is a great starting point. And essential for understanding dog color genetics.

Continue here if you feel ready for some genetics basics.