French Bulldog Colors and DNA | Understanding Crazy Genetics

By: Danielle Harris

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French Bulldogs come in many different colors and patterns.

French bulldog colors and Types of French bulldog colors include:


  • Pied
  • Ticked
  • Irish or Blanket Pied (only 1 copy pied)
  • Brindle
  • Fawn/sable
  • Blue
  • Lilac
  • Chocolate
  • Rojo
  • Isabella, New Shade
  • Cream
  • Platinum (lilac covered in cream)
  • Merle
  • Tan Points

Colors and Hair lengths we wont be covering:

  • Urajiro – they dont know what makes it
  • Pink
  • Husky
  • Koi
  • Fluffy
  • Velvet
  • Hairless
  • Curly
  • Rough

I find color dna to be absolutely fascinating and the combinations are endless!

Animal Genetics and UC Davis offer Health and Color testing.

If you’re in a pinch and don’t want to wait for test kits to arrive.

Decide on what tools you need based on what company you use and what kind of sample you would like to run.

Uc Davis only takes oral swabs. Animal Genetics takes oral swabs, dew claws, and blood samples.

Go to animal genetics login and create an account to get started!

If you need help interpreting your test results, send us a message.

Do you know the colors and patterns of French bulldogs?

Pied French Bulldog
French Bulldog Colors

Pied or Piebald

Pied is when a French bulldog is predominantly white with colored spotting.

Blanket pied or Irish pied happens when the dog is almost solid in color with white being on the underside of the dog and ONLY 1 copy of pied. “They” don’t know what causes this but “they” believe other factors are involved.

Pieds can come in all colors including brindle and merle.

Although rare, ticking also happens in pied dogs. It’s not desired by AKC but still accepted.

Elsa is ticked.

We love pied French bulldog.

French bulldog spotted is another term people use.

Brindle French bulldog


Brindle french bulldogs is when the dog is “striped”.

The dog can be almost any color with brindling: lilac, blue, chocolate, pied, Isabella.

Brindle is dominant over everything including fawn/sable. However, a dog can be Cream/Platinum or cream covering color, including brindle.

The only way to know if a Cream/Platinum dog is brindle is to do a color test.

Brindle always has at least one copy “ay” fawn.

Trindle has one copy kbr and has at/at or at/a at the “a” locus.


Trindle is a variation of Brindle.

Trindle French Bulldog

Because brindle “KBR” only affects the “a” locus, there are two genes it can affect. “AY” and “AT”. “Ay” fawn is a full body color while “at” tan points are only on the feet, cheeks, and eyebrows.

Trindle dogs always have “at/at” or “at/a”

This is why you see brindling on the feet, cheeks, and eyebrows in trindle dogs.

Some dna of trindle:

at/at ky/kbr

at/at kbr/kbr

at/a ky/kbr

at/a kbr/kbr

Sable French Bulldog
Red and Blue Sable French Bulldog Puppies
Fawn french bulldog
Lilac Fawn French Bulldog


Fawn/Sable is when the dog is a sandy color. These colors also come in all shades from light tan to deep red.

Shades depend on the other locus alleles contributed.

They can be blue fawn, chocolate fawn, chocolate, lilac, or Isabella fawn.

These dogs cannot express tan or tricolored points.

This color is also dominant, over all colors except Brindle and Cream.

The fawn French bulldog is the quintessential Frenchie color.

Pictured here above is Sasha, a Lilac Fawn, Female French Bulldog.

Blue fawn colour french bulldog are similar in color.

Sable is when the dog has dark tipped hair. Sables have the dna of ay/at.

Blue pied French Bulldog

Blue – Dilute

Blue Dilute is when the dog is “grey” or “silver” in color. Blue is a dilution of other colors. The gene causes a mutation in cells that cause the color to improperly align, giving the diluted coat color.

Both Ziggy and Dahlia are Blue French Bulldogs.

Chocolate or Coco

Coco is previously known as “untestable”.

2 copies of the allele are needed in order to express the coat as chocolate. 2 carriers bred together can create a full chocolate dog.

This is one of 2 of the chocolate gene.

This is the gene that causes red eye french bulldog. The red eye glow will show up in most carriers.

french bulldog longer snout
Solid Coco Chocolate French Bulldog

Rojo – Testable Chocolate

rojo french bulldog

The other chocolate, known as Testable, is found on the B locus.

B locus is actually responsible for dominant black.

However, when 2 copies of “b” are passed on, the dog will then express a chocolate or liver coat. “bb” is actually a mutation, like dilution blue.

“bb” is now known as Rojo. Rojo is “bb” on its own. The dna can carry all the other colors but to be a rojo the dog must not have 2 copies of blue or coco.

This is known as red in other breeds such as doberman and kelpie.

lilac tan french bulldog


Lilac is a combination of full blue and full chocolate. The dna for lilac is “d/d co/co”

Pictured here is one of our own pups, “d/d, co/co, at/at”


An Isabella French bulldog is a Testable Chocolate “b/b” combined with Blue “d/d”.

To result in “d/d, b/b”.

Some people also call this Lilac. However, lilac is ALWAYS dd coco.

Isabella is more of a light Caramel color whereas lilac is a lighter blue/silver color.

New shades include for example: New Shade Isabella results in dna of “d/d, b/b, co/co”

Isabella can also be covered in cream.


Cream, different than fawn. A Cream French bulldog dog is literally the color of cream.

cream french bulldog
Cream French Bulldog

Cream French bulldogs can carry other colors or even genetically be something else in combination with cream. Cream covering blue, chocolate, brindle, Lilac which is then called Platinum. Our “white” Doberman is best explained to people as platinum or covered in cream. The cream French bulldog is highly sought after.


Platinum is a Lilac dog “dd coco” covered in cream. The dna is then “dd coco ee”.

Other colors can also be covered in cream.

Blue covered in cream, chocolate, tan/tri points, Isabella.

However, these are not a true Platinums. Platinum is always Lilac covered in cream.

You’ll find that people commonly call all cream French bulldog covering color, platinum, even I make the mistake.


A Champagne dog is a chocolate or testable chocolate covered in cream. “bb ee” or “coco ee”

tan point french bulldog

Tan Color or Tan Point

Tan and Tri Color is determined by the A locus – “at” allele.

This gene only expresses if the dna is at/at, at/a, and with no K locus present or ky/ky.

Dogs with at/at can be for example: Black and tan or Black tri. Tri means the dog has black, tan, and white.


Merle is a color coat pattern. It can come in ANY color. Our favorites are blue merle and lilac merles. It creates mottled spots, odd color eyes, and can affect skin pigment.

This gene only needs one copy to express and is dominant. Because of this, 2 merles should never be bred together. The chances of birth defects and health problems is a significant concern when breeding 2 merles together. Many double merles have vision and hearing deficits.

When purchasing a pup from a litter that has merles, for breeding purposes, test the puppy to make sure it is not a cryptic merle. Cryptic or phantom merle is when the dog has the merle gene but does not express it or has faint unnoticeable patches, most often found in fawns and creams.

Merle french bulldog

Do you know the color and pattern panels and DNA?

Knowing the panels and how they affect color and pattern will help you to make decisions based on the goals of your program. If you’re into the “fad” colors you’ll want to avoid fawn and brindle. Some “high end” French bulldog breeders also avoid pied. We like pied. They can come in every color.

Here, we explain what each locus does, what colors they make, and how dominant they are.

Blue Fawn Merle French Bulldog
Blue Fawn Merle French Bulldog

A locus – fawn, sable, tri color

There are four different alleles identified in a dog’s genes that give the agouti coloration also known as the A locus. These alleles are “ay”, “aw”, “at”, and “a”. This color is much like that of a rabbit except “a” which is recessive black and at which is tan point or tri color.

solid french bulldog
Solid Chocolate French Bulldog

These alleles are dominant in a chain of command. This means that “ay” is more dominant than “aw”, “aw” is more dominant than “at”, and “at” is more dominant than “a”. For example, if a dog is “ay/at”, the color of the dog will be fawn.

However, this is all dependent on whether the dog carries the dominant black gene K locus or the recessive gene “e” on the E locus or not.

If a dog carries one or both of these genes, the A locus is muted, and the A locus coloration will not appear on the dog.

This is because both the K locus and the E locus are dominant over the A locus.

The agouti gene determines the base coat color in dogs that are “ky/ky” for dominant black. Dogs must be “ky/ky” in order to express any alleles on the A locus.

The color of the dog can still be altered by other genes, such as by the B locus or D locus, however. For example, if a dog is “b/b” (testable chocolate), it will be modified to appear as a chocolate pigment.

However, if a dog’s A locus is “ay/at” or “ay/ay”, and the dog is also “b/b”, the fawn dog will have a chocolate nose. A dog that is “at/at” will have a chocolate and tan coat.

If a dog is n/n for the gene, that means that the dog will not express any coloration associated with this gene.

The “ay” Allele

The “ay” allele is the most dominant of all four alleles. This gene produces a range of colors like light fawn colors, darker red colors, or even sable. Dogs that are “ky/ky” and have two copies of “ay” will always express the “ay” Fawn coat. This is because the “ay” allele is more dominant than the “ky” allele. Dogs that have one “ay” and one “at” will be sable. It is important to know that a dog can appear as fawn or sable BUT could also carry any other of the three alleles. These other alleles will never fully express. 

A dog that has two copies of “ay” will always pass on the “ay” allele. If that dog is bred to another dog that is n/n (recessive) for the K locus, the dog will always produce fawn or sable pups.

The “aw” Allele

The “aw” allele produces a color known as “wild sable.” With this coloration, the hairs switch pigmentation from a black color(on the tips) to a reddish or fawn base color. It is recessive only to the “ay” allele. This also means that it is dominant over the “at” and “a” alleles and will be expressed before the “at” and “a” alleles.

The “at” Allele

Both the black and tan and tricolor are produced by the “at” allele. A tricolor dog is black and tan with white. White is generally just an absence of color, rather than a pigment the dog expresses. For a dog to be black and tan or tricolor, he must be “n/n” for the dominant black gene (the K locus).

This means that the K locus is not expressed, and the dog will not be black. Also, the dog must have either two copies of the “at”, or have one copy of at and one copy of a. The dog must be n/n for both the “ay” and “aw” alleles in order for “at” to be expressed. A dog that is “at/at” will always pass on a copy of the “at” allele to any offspring. This does not ensure that the puppies will be black and tan. The coat color of the offspring also depends on the genes of the other parent.

The “a” Allele – Solid

If a dog is “ky/ky”, the dog must be “n/n” for “ay”, “aw”, and “at” for the dog to express the a/a color. A dog that is solid black with the recessive K locus must also have the recessive a/a allele in order to express the black coloration. This is rare because the “a” is recessive. It is important to make sure you know the dna of both parents. Because a dog can also be solid black with “kb/kb” or “kb/ky”, To determine if the dog is “a/a” or expressing with k locus, a dna color test will be needed.

The “a” allele is sometimes referred to as the recessive black gene. Because this allele is the most recessive of the four, for a dog to express this phenotype he must have two copies of the “a” allele. A full recessive black dog will always pass on the “a” allele to all offspring.

aa can also be present in other colors. Our Chocolate stud Chewy is solid chocolate with the dna of: aa Dd coco L4.

B locus – Black/Brown (testable Chocolate)

In the dominant form of the B Locus, tyrosinase-related protein 1 is produced. This protein produces a pigment called eumelanin. Enough eumelanin is produced so that the dog’s coat appears black instead of chocolate. This dominant form appears when the dog has the “B” allele vs “b”.

A mutation in the gene can occur, causing a change in the production of the eumelanin. This dilutes the black color pigment into a brown color. This mutated gene is known as the “b” allele or Testable Chocolate.

When a dog has two copies of the recessive allele “b/b”, all black pigment appears brown. This color can also be referred to as liver or chocolate.

However, the B allele is dominant over the b allele. Therefore, a dog that is B/b or B/B will have a black coat, and not chocolate. The dog must have b/b in order to have the brown coloration.

Because B locus is only associated with eumelanin, this mutation only influences coat color of dogs that are “E/E or E/e”.

Co locus – Chocolate, “untestable”

“b/b” variants in B locus are the most common cause of brown, chocolate or liver coat color.  There are currently a total of five known B locus “b” gene mutations(not listed, its too confusing) that impact the genes functionality, explaining most dogs with brown coat and nose color.  

chocolate french bulldog
Cocoa French Bulldog Puppy

One exception is the brown or chocolate French bulldog, which remained a mystery as to the cause.  In 2014 Animal Genetics tested the B locus gene of several brown French bulldogs but was not able to find any functional variants that produced the brown coat color. Recently, research conducted in University of Bern in Switzerland revealed a nonsense variant. In this study, the brown or chocolate dog was affected by a mutation – “co/co” allele.  

Animal Genetics conducted whole genome sequencing on 3 brown or chocolate French bulldogs. 2 were negative for all B allele mutations and one brown dog that carried one copy of the recessive form of B allele (“b”). The research showed the same correlation between the recessive coco allele and the look of the dog.

Differences in coat, skin and eye color between B locus and Coco dogs are subtle but clear. With two copies of cocoa having a slightly darker coat color and lighter eyes than the more common B related brown dogs. This also causes red eye glow even in carriers. The red eye french bulldog is not seen in testable dogs unless they also carry coco.

K locus – Dominant Black, Brindle

Coat color is controlled by several different genes in dogs. The K locus, also known as the dominant black gene.

The K locus is dependent on the E locus. If the E locus is “e/e” (recessive yellow/red- cream), the K locus is not expressed. However, if the E locus is “E/E or E/e”, the K locus is still expressed.

The “kb” Allele

The dominant black gene consists of three different alleles. The first allele, which is dominant, is notated as “kb,” or dominant black. The dominant black allele is actually a mutation that reduces or eliminates the expression of the agouti gene (A locus). Because this mutation is dominant, a dog only needs to have one copy of the mutation to affect the agouti locus. If a dog is “kb/kb” or “kb/n” that means that they will be solid black in color.

The “kbr” Allele

The second allele is known as the “brindling” allele and is labeled as “kbr”. “kbr” is a separate mutation that allows the A locus to be expressed. However, it causes a brindling of that color. The A locus represents several different colors, such as fawn/sable, tricolor, tan points, or recessive black. The “kbr” allele is recessive to the “kb” allele. This means that if a dog is “kb/kbr”, they will still be black in color. “kbr” is, however, dominant over the third allele, “ky”.

Bella The Blue Brindle! Brindle is ONLY ay/kbr. Ay/fawn affects the entire body color, which is why “kbr ay” is brindle. “at” affects only paws, cheeks, and eyebrows. “Kbr” combined with “at” will produce a trindle.

The “ky” Allele

The third allele is named as “ky”. This allele allows the agouti gene to be expressed without brindling. If a dog is “ky/ky”, the A locus then determines the dog’s coat color. The “ky” allele is recessive to both “kb” and “kbr”. This means that if the dog is “kb/ky” or “kbr/ky”, the dog will not express the A locus like a “ky/ky” dog would.

For example, a dog that is “ay/ay” at the A locus could be fawn/sable if the dog is “ky/ky”. However, if that same dog is “kb/kb”, the A locus color will be muted. Dahlia is “kb/n” which is why her “at/at” does not show. However, if that same dog is “ky/ky”, he will then be able to express A locus color and will be fawn/sable.

D locus – Blue

The protein called melanophilin, is responsible for transporting and fixing melanin-containing cells. A mutation in this gene leads to improper distribution of these cells, causing a diluted coat color. The mutation causing color dilution is recessive, and two copies of the mutated gene (the D allele or the D locus) are needed to produce the diluted coat color.

blue french bulldog

The MLPH mutation affects both eumelanin and phaeomelanin pigments. These pigments control the color of the dog. Black, brown, and yellow/Cream dogs can all be affected by the D locus. However, the effects of the dilution are more pronounced in black dogs. A diluted dog becomes known as a blue dog. A diluted chocolate dog is often referred to as a lilac (“dd coco”) or Isabella(“dd bb”) and a diluted yellow dog/cream is often called champagne. Dogs that express the diluted are “d/d” in combination with any other color coat code. Brindling does express in dilution.

Because the mutations responsible for the dilution are recessive, a dog can carry one copy and still express a normal coat color. These dogs can pass on either the full colored genes or the dilution to any offspring. This means that two dogs that are full colored can produce a diluted puppy, as long as both parents carry one copy of the dilution.

E locus – Mask, recessive red/yellow/cream

The extension gene, controls production of pigment in melanocytes. Melanocytes are cells that control the coloration of skin or fur. The dominant form of the gene, “E” allele, allows the dog to produce eumelanin, which is a black pigment. This can appear either as “E/e” or “E/E”.

A mutation in the gene causes the pigment-producing cells to only produce phaeomelanin instead of eumelanin. This turns all the eumelanin in the coat to phaeomelanin. This form of the gene is represented as the “e” allele. The e allele is recessive (“e/e”), meaning that a dog must have two copies of the MC1R mutation to express the yellow/cream or red coat color. Recessive red can mask other colors. It can even mask the merle coloration. “e/e” in frenchies is known as Cream!

A third allele exists in the extension gene: “em”. “em” is also dominant. This means a dog can have “em/e” or “em/em” for the “em” color to express. This causes the dog to have a black mask on their face, also known as a melanistic mask.

This allele acts similarly to the E allele in that it causes a black-based coat. Because it is dominant, a dog only needs one copy of the “em” allele to express. In solid black dogs with one copy of the “em” allele, the mask is hidden. This is because the mask and the fur color are both black, and the mask then becomes “invisible.” However, the dog can still pass on the melanistic mask to future offspring, even if the mask cannot be seen. It is also hidden in Dilute dogs.

pied french bulldog

S locus – Pied, spotting

Piebald is a coat pattern.

In many breeds, piebald acts as a “dosage” trait. This means that the amount of white a dog expresses depends on how many copies of the S allele a dog carries. Dogs like the French Bulldog who have a single copy of the S locus allele will express no white spotting pattern. Dogs that have 2 copies “S/S” will exhibit more white with very little color. Pied French bulldog can come in ANY color. they can be lilac French bulldog, blue French bulldog, merle French bulldog and more.

Some carriers of Pied may come out looking like a Pied. This is called Irish pied. Irish pied is not a true pied due to only one copy but has the spotting of one. Science hasn’t figured out what causes Irish pied. Most breeders who produce Irish pied are convinced theres more to it than just carrying one copy.

M locus- Merle

Merle is a coat pattern. The merle gene creates mottled patches of color in a solid or piebald coat, blue or weird colored eyes, and affects skin pigment. Dogs that are “double merle,” a common term used for dogs that have two copies of the merle “M/M” trait, are predominantly white and prone to several health issues.  

The chances of having puppies that develop health issues increase when two merles are bred together. A merle dog should ONLY be bred to a non-merle/non-cryptic Merle dog.

Cryptic merle dogs do not appear to be merle but contain the merle gene. Many solid dogs are actually cryptic, also known as phantom, and can produce both merle and double merles if not careful.

If you purchase a puppy from a litter with merles, for breeding purposes, a dna test is required to make sure you don’t breed to create an accidental double merle.

Merle can affect all coat colors. Combinations such as brindle merle and pied merle also exist.

In addition to altering coat color, merle can also change eye color and the coloring of the nose and paw pads. The merle gene modifies the dark pigment in the eyes, occasionally changing dark eyes to blue, changing only one eye, or only part of the eye. This is highly sought after. Since Merle causes random modifications, both dark-eyed, blue-eyed, and odd-colored eyes are possible but not guaranteed. Color on paw pads and nose may be mottled pink and black.

merle french bulldog

Intensity (Intensive) Dilution

isabella new shade french bulldog

Mammals produce two kinds of pigment: eumelanin (black and/or brown in color) and phaeomelanin (red and/or yellow in color).

Many genes contribute to the type and amount of pigment produced.

Several breeds of dogs have an extreme dilution phenotype that has been shown to only affect the red pigment phaeomelanin. This change in the DNA results in an amino acid difference in the protein where cysteine replaces the normal arginine at amino acid 51 (p.Arg51Cys).

This mutation is predicted to have damaging effect on protein function.

MFSD12 is believed to function as a lysosomal transmembrane solute transporter directly affecting the production of phaeomleanin. In dogs, the MFSD12 In variant has only been shown to decrease red/yellow pigment leaving black/brown pigment unaffected.

In frenchies the intensity gene affects the cream gene “e/e”. If there are 2 copies of intensity in a cream Frenchie “e/e”, their coat will appear cream to pure white in color.

See above picture from Dezinerbullz showing intensive Isabellas.

Breed standard colors recognized by the American Kennel Club are: brindle, fawn, white or cream, and pied.

There’s so much genetic variability and results are case sensitive (meaning there is a difference in b vs B).

We love animal science and animal breeding.

If you have any questions about your French bulldogs DNA and color reach out to us! We’re happy to help!

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6 thoughts on “French Bulldog Colors and DNA | Understanding Crazy Genetics”

  1. Really interesting and informative.
    I have a platinum lylac dog and a dark brindle bitch, is there any possibility of knowing what colour pups they would probably have ?.



  2. Hi! This is so detailed! And also a little confusing when trying to learn lol. Any tips on how or where to go to learn this in a simplified way? And another question.‘I have a Merle black and tan harlequin Frenchie, but I’m confused on what makes him a harlequin, I was under the impression it was the giant big dark spot he has, the front half of him is spotted white grey black and tan, and he has like green eyes (never seen eyes his Color before) and then his back is all dark, just one giant dark spot.. anyways could you explain this a bit more ?

  3. What do I consider mine to be? Haven’t seen one like her yet!
    She is mostly all white with a few light tan spots on her back. Pink ears nose and around eyes. Eye color is light green. Beautiful girl!!!

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