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Blue Boston Terrier: Why They Are Blue, Temperament & Issues

Blue Boston Terriers are grey with a blue shade when you look at them from specific angles. They are not a separate breed from Boston Terriers, but merely a different color than the standard.

The color of blue Boston Terriers is determined by an interaction of genes. 

Even though this color is loved by many owners, blue Boston Terriers are not as popular as other colors. 

The price of a blue Boston Terrier varies depending on the region you live in because some areas have fewer breeders than others.

This article explains why some Boston terriers are blue. It also details what other color mixes of blue Boston Terriers can display. 

Why Is a Blue Boston Terrier Blue?

Blue Boston Terriers are actually a light shade of grey which has a blue-is appearance. This color is caused by a combination of genes. One is responsible for the color and the other for the dilution of the color. 

The color of Boston Terriers is determined by two primary pigments: 

  • Eumelanin
  • Pheomelanin

Eumelanin makes dogs’ hair black or brown, while pheomelanin makes it red. 

The genes that determine where each pigment lies on a dog’s body interact with other genes. One of these genes is the one responsible for color dilution, causing a blue shade for gray dogs.

If the dog’s color was dominated by pheomelanin (meaning it has a red base), the interaction with the dilution gene would result in yellow or creme instead of blue.

The Blue Boston Terrier’s coat color is determined by eumelanin. As a result, it should be black. But the black is diluted, and when black is diluted, it turns grey. 

Blue Boston Terriers have a blueish glow, this is why people call it blue. They are not actually blue.

The gene responsible for the blue color of a Boston Terrier’s coat is recessive. Recessive genes need to be passed on by both parents to manifest. 

This doesn’t mean that both parents of a Blue Boston Terrier need to be blue. They can be carriers and pass on the gene to their offspring.

Why Is a Blue Boston Terrier Blue
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Blue Boston Terriers Appearance

Blue Boston Terriers are small and athletic dogs. They have round heads and prominent eyes. Their noses and upper jaw are short, which sometimes causes health issues. 

The blue Boston Terrier has short hair which lies close to its body. Their slick appearance highlights their muscles, this is why they have an athletic appearance. 

Blue Bostons are single-coated and shed moderately. Contrary to popular belief, they are not hypoallergenic. 

This table lists the main traits of blue Boston Terriers.

Height15 – 17  inches
Weight12 – 25 pounds
Lifespan11 – 13 years
Dog Breed GroupPure breed
Coat TypeSingle
Coat LengthShort
Coat ColorPure blue, blue and white, blue-brindle and white, blue-merle and white, blue-fawn and white, blue-red and white
EyesDark or blue
NoseBlack or gray
Grooming Difficulty2

Blue Boston Terrier Colors

Blue Boston Terriers can be pure blue but this situation is rare because most American Gentlemen carry the gene for white markings. 

The Blue Boston Terrier comes in a variety of supporting colors:

  1. Blue and White Boston Terrier
  2. Blue Brindle Boston Terrier
  3. Blue Merle Boston Terrier
  4. Blue Fawn Boston Terrier
  5. Blue Red Boston Terrier

1. Blue and White Boston Terrier

Blue and White Boston Terrier
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The majority of Blue Boston Terriers display white markings. These markings have a specific location.

White hair in dogs is not the result of coloration, but a lack of coloration. The white markings on a blue Boston Terrier lack melanin, the pigment responsible for color.

Blue and white Boston Terriers are bicolored. They don’t have any other markings or colors.

The American Kennel Club requires Boston Terriers to have:

  • A white chest
  • A white band on the muzzle
  • A white blaze bet

2. Blue Brindle Boston Terrier

Blue Boston Terriers rarely display the brindle pattern. The brindle pattern is similar to tiger stripes but the contrast between the base color and the stripes is not as noticeable as in tigers. 

Blue Brindle Boston Terriers are rare because the genes responsible for their color are recessive. The dilution gene and the gene that determines the brindle pattern need to be passed on by both parents to manifest. 

3. Blue Merle Boston Terrier

Blue Merle Boston Terrier
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Blue merle Boston Terriers display coats with irregular patches. Some patches are diluted, while others have a solid color. 

The merle pattern is common only to dogs whose coat color is determined by eumelanin. As a result, red Boston Terriers can not display the merle pattern but their puppies can.

4. Blue Fawn Boston Terrier

The blue fawn Boston Terrier is the result of breeding blue with fawn Bostons. This color is determined by a gene called Augouti.[1]  

The Agouti gene determines how melanin is released into the hair. As a result, it is responsible for the switch between eumelanin and pheomelanin. 

5. Blue Red Boston Terriers

There is not enough documentation about blue-red Boston Terriers because they are uncommon. They are the result of accidental breeding. Certified breeders don’t sell blue-red Boston Terriers.

Related: 13 Boston Terrier Colors

Blue Boston Terrier Temperament

Blue Boston Terriers are friendly and loving dogs who suit well to apartment living. Still, they have a predisposition for aggression, which is related to the purpose they have been bred for, pit fights. 

Boston Terriers were initially bred for pit fights. This made the part of their brain responsible for aggression to be more active. This trait has been passed on for generations, and blue Boston Terriers are predisposed to aggression. 

Yet, they are calm and kind dogs if they are trained and socialized in puppyhood.

Blue Boston Terriers are intelligent and fun to be around. They easily understand what humans want them to do but are sometimes stubborn and self-willed. 

This means their trainer needs to be patient and firm. 

Blue Boston Terrier Temperament
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Are Blue Boston Terriers Healthy?

Yes, blue Boston Terriers are as healthy, like other Bostons. Their color does not influence their health, as the genes responsible for this phenotype are not associated with any health issue. 

Blue Boston terriers suffer from specific health issues only if they are merle. The gene responsible for the merle pattern is correlated with sterility, deafness, and blindness[2].

The specific health conditions of Boston Terriers are:

  • Cataracts[3]
  • Glaucoma[4]
  • Corneal ulcerations
  • Deafness[5]
  • Patellar luxation[6]
  • Brachycephalic obstructive airway syndrome[7]

Related: 16 Boston Terrier Health Issues

Are Blue Boston Terriers Accepted By The American Club?

No, blue Boston Terriers are not accepted by the American Kennel Club. The breed’s accepted color standard is as follows:

  • Brindle with white markings
  • Brown with white markings
  • Black with white markings.

Blue Boston Terrier puppies have gray or blue eyes which turn darker as they age. Sometimes their eyes remain the same. 

Boston Terriers with blue eyes are not accepted by the AKC.

How Much Do Blue Boston Terrier Puppies Cost?

Blue Boston Terrier puppies cost between $600 and $1000. They can cost more if they come from a renowned breeder who socializes the puppies early.

The price of blue Boston Terriers is influenced by:

  • Their popularity in the area
  • The breeder’s reputation
  • Their age
  • The training they received prior to the purchase
  • The medical costs supported by the breeder

Related: Average Price of a Boston Terrier


The blue Boston Terrier is a loving family dog who likes to be around people. They love other dogs but don’t mind being alone. Their color is actually grey and has a blue shade. This color is the result of a gene that dilutes black. 

Blue Bostons have a sophisticated appearance. They are rare in some areas and can be expensive if they have been previously trained. Blue Bostons have a unique color and have an imposing stature, even though they are small.

About Ioana Moldovan

Ioana is a Misfit Animals staff writer and psychology student interested in animal behavior. She likes to dive deep into the newest scientific studies to find out the latest discoveries in the field.

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