> ## Content Index > Fetch the complete content index at: https://equinecolors.com/llms.txt > Use this file to discover other available public pages before exploring further. # Bay - URL: https://equinecolors.com/bay/ - Published: 2025-11-04T19:25:04.000Z - Updated: 2026-08-10T09:50:22.000Z - Description: Bay is one of the base coat colours in horses, alongside chestnut and black. It is defined by a red coat with black points in a wide range of shades. - Author: Hannelore Roodhooft - Tags: Colors, Base colors, #Import 2026-08-12 09:42 ## Appearance Bay horses have a reddish coat with black [points](https://equinecolors.com/dictionary/#:~:text=Horse%20Terms-,Points,-The%20mane%2C%20tail). Splashed white patterns tend to express more loudly on black/bay-based horses. | Foals | ![Bay foal](https://equinecolors.com/content/images/2025/11/bayfoal.png) | Bay foals have a **reddish** coat with **black points**, though their legs often appear **lighter** or greyish in color. The [**soft parts**](https://equinecolors.com/dictionary/#:~:text=into%20their%20surroundings.-,Soft%20parts,-The%20soft%20parts) usually have a **paler** shade and the **mane and tail** can have **lighter hairs** in them as a result of [foal camo](https://equinecolors.com/dictionary/#:~:text=a%20bay%20horse.-,Foal%20Camo,-Foals%20are%20often). | | ----- | ------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Bay horses have **black points** on their legs that goup to their knees and hocks. They have a **reddish** coat, and their shade can vary from a very light **copper bay to blood bay**. | ![bay horse](https://equinecolors.com/content/images/2025/11/bay.png) | Adults | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------- | ------ | ### Bay shade variations Bay horses come in many different shades. Two commonly used terms for these bay variations are **seal brown** and **wild** (low-point) **bay**. The exact genetics behind these are still unknown and often debated. | SealBrown | ![Seal brown horse](https://equinecolors.com/content/images/2025/11/seal.png) | Seal brown is a **dark variation** of bay. Horses can sometimes appear nearly "black", but the **soft parts** are still **red** colored. Seal brown foals are **born** with their darker color. | | --------- | ----------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | WildBay | ![Wild bay horse](https://equinecolors.com/content/images/2025/11/wildbay.png) | Wild or low-point bay can be recognised by the**low black points** (up to the pasterns or fetlocks)and usually a **lighter, more yellow** shade of bay. The knees and hocks may have some dark/black smudges on them. Since the points of a foal can take years to fill in, wild bay **can't be seen on foals** or young horses (\~ <5 years). | | ------- | ------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ### Bay variations | Sootybay | ![Bay sooty](https://equinecolors.com/content/images/2026/01/baysooty.png) | | -------- | -------------------------------------------------------------------------- | ### Mimics Other colors can look similar to bay. ![CTA Image](https://equinecolors.com/content/images/2025/12/Equinecolors_Icon_MagnifyingGlass-2.png) Look at the ****points** of the horse. These should be ****black** in color. Look at the ****soft parts** of the horse. These parts should be ****reddish** in color. ## Genetics The base colour bay is controlled by the **extension** [**gene**](https://equinecolors.com/dictionary/#:~:text=in%20each%20pair.-,Gene,-A%20gene%20is) and the **agouti gene**. The **extension** gene controls the production of red and black pigment. Horses need at least one copy of the [dominant](https://equinecolors.com/dictionary/#:~:text=Dominant%20Allele%20%28written%20in%20capital%20letters%29) E-[allele](https://equinecolors.com/dictionary/#:~:text=on%20a%20chromosome.-,Alleles,-Different%20versions%20of) **(E/E or E/e)** to be able to produce black pigment. The **agouti** gene controls the distribution of black pigment. The dominant A-allele causes black pigment to be restricted to the points of the horse. As a result, horses need at least one copy of the a-allele **(A/a or A/A)** to be bay. ![CTA Image](https://equinecolors.com/content/images/2025/12/Equinecolors_Icon_DNA1-8.png) Bay: E/E + A/A E/E + A/a E/e + A/A E/e + A/a ### Genetics of Bay variations For some time, **seal brown** was believed to be caused by the **At allele** of agouti ([dominance](https://equinecolors.com/dictionary/#:~:text=How%20Alleles%20Influence%20Coat%20Color): A > At > a). A DNA test existed, but no scientific papers were published, the results were **inconclusive**, and the test was withdrawn. This theory is no longer supported. Similarly, **wild bay** (or low-point bay) was theorised to be caused by the **A+ allele** (dominance: A+ \> A > a). This idea has also been discarded. > *You can still find these older theories and shade names *used in many places*, which is why I like to mention them here. It is also how bay genetics work in our game,* [***Horse Reality***](https://www.horsereality.com/?ref=equinecolors.com)*. At the time of development, the At and A\+ theories were still alive. Even so, for any color we *don't know the genetics* of yet, we have to come up with something to make it work in-game. Which means working with just *observations and theories*.* Currently, we have some theories as to what actually causes the different shades of bay. One study1 found that **E/E A/a** **bays** tend to be the **darkest** and are typically **seal brown** in color. Another study2 confirmed that E/E bays tend to be darker. They also found a **DNA region**, close to the agouti gene, that possibly **controls bay shade**. That's all we know for now, but it seems like the extension gene acts "[incomplete dominant](https://equinecolors.com/dictionary/#:~:text=e%20is%20different.-,Incomplete%20Dominant,-One%20allele%20does)" in some way. We'll have to wait for more research to come out about the shade region. ## Presence in horses Bay dun (E/E A/A) is considered the wild type or "original" horse color. All other coat colors are the result of mutations. Unsurprisingly, bay-based horses are widespread and common in many horse breeds. **Read more:** [Chestnut](https://equinecolors.com/chestnut/) | [Black](https://equinecolors.com/black/) |[ Sooty bay ](https://equinecolors.com/sooty-bay/)| [Bay pangaré](https://equinecolors.com/bay-pangare/) [Back to Base Colors](https://equinecolors.com/base-colors/) ## Articles 1. Corbin LJ, Pope J, Sanson J, Antczak DF, Miller D, Sadeghi R, Brooks SA.; **A*n Independent Locus Upstream of ASIP Controls Variation in the Shade of the Bay Coat Colour in Horses***; *Genes* (2020); Doi: [10.3390/genes11060606](https://doi.org/10.3390/genes11060606?ref=equinecolors.com) 2. Druml T, Grilz-Seger G, Horna M, Brem G.; ***Discriminant analysis of colour measurements reveals allele dosage effect of ASIP/MC1R in bay horses***; Czech J. Anim. Sci. (2018); Doi: [10.17221/105/2017-CJAS](https://cjas.agriculturejournals.cz/artkey/cjs-201809-0002%5Fdiscriminant-analysis-of-colour-measurements-reveals-allele-dosage-effect-of-asip-mc1r-in-bay-horses.php?ref=equinecolors.com) 3. Rieder, S., Taourit, S., Mariat, D., Langlois, B., Guerin, G.; ***Mutations in the agouti (ASIP), the extension (MC1R), and the brown (TYRP1) loci and their association to coat color phenotypes in horses (Equus caballus)***; Mammalian Genome (2001) Doi: [10.1007/s003350020017](https://link.springer.com/article/10.1007/s003350020017?ref=equinecolors.com) ### Seal brown references - [PetDNA Services of Arizona - Understanding Equine DNA and Agout](https://web.archive.org/web/20140823030201/http://www.petdnaservicesaz.com:80/equine-testing/understanding-equine-dna-and-agouti/)[i](https://web.archive.org/web/20140823030201/http://www.petdnaservicesaz.com:80/equine-testing/understanding-equine-dna-and-agouti/) \- Archived copy - [PetDNA Services of Arizona - At testing](https://web.archive.org/web/20150415032848/http://www.petdnaservicesaz.com/equine-testing) \- Archived copy --- [![CTA Image](https://equinecolors.com/content/images/2025/10/Image-5.png)](https://www.horsereality.com/?ref=equinecolors.com) Learn while playing! Discover how genes shape colors and patterns in our realistic horse breeding game, Horse Reality [Play now ](https://www.horsereality.com/?ref=equinecolors.com)