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# Bay mushroom
- URL: https://equinecolors.com/bay-mushroom/
- Published: 2026-02-05T13:22:40.000Z
- Updated: 2026-08-10T10:54:57.000Z
- Description: Bay mushroom is the result of a bay base coat diluted by mushroom.
- Author: Hannelore Roodhooft
- Tags: Colors, Dilutions, #Import 2026-08-12 09:42

## Appearance

| Foals | ![Bay mushroom foal](https://equinecolors.com/content/images/2026/02/baymushroomfoal.png) | Foals have **"muted" [](https://equinecolors.com/bay/)** **bay** color. |
| ----- | ----------------------------------------------------------------------------------------- | ----------------------------------------------------------------------- |

| Bay mushrooms lack the reddish hueof a typical bay coat, often with darker [**countershading**](https://equinecolors.com/dictionary/#:~:text=Horse%20Terms-,Countershading,-Darker%20color%20on). | ![Bay mushroom](https://equinecolors.com/content/images/2026/01/baymushroom-1.png) | Adults |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------- | ------ |

### Mimics

Mushroom has a less obvious effect on bay compared to chestnut, so it can be harder to see.

## Genetics

Bay mushroom is the result of a **bay base** diluted by **two copies of mushroom**. The mushroom (mu) dilution is an allele of the [**MFSD12**](https://equinecolors.com/mfsd12-gene/) gene.

![CTA Image](https://equinecolors.com/content/images/2025/12/Equinecolors_Icon_DNA1-17.png) 

****Bay mushroom:**  
Bay (E/\_ A/\_) + mu/mu

Horses with only one copy of mushroom are called mushroom carriers. They might not show a visible difference, but they can pass the [allele](https://equinecolors.com/dictionary/#:~:text=the%20DNA%20sequence-,Alleles,-Different%20versions%20of) on to their foals!

  
**Read more:**  
[Bay](https://equinecolors.com/bay/) | [Chestnut mushroom](https://equinecolors.com/chestnut-mushroom/) | [Buckskin mushroom](https://equinecolors.com/buckskin-mushroom/)

[Back to Mushroom](https://equinecolors.com/mushroom/)

## Articles

1. Tanaka, J., Leeb, T., Rushton, J., Famula, T.R., Mack, M., Jagannathan, V., Flury, C., Bachmann, I., Eberth, J., McDonnell, S.M., Penedo, M.C.T., Bellone, R.R.; **Frameshift Variant in MFSD12 Explains the Mushroom Coat Color Dilution in Shetland Ponies**; Genes *(*2019); Doi: [10.3390/genes10100826](http://dx.doi.org/10.3390/genes10100826?ref=equinecolors.com)

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