Mushroom is a rare and newly discovered dilution that isn’t very well documented. While it looks very similar to (and is usually registered as) silver dapple, it occurs in animals that don’t carry the silver gene in their DNA.
Only a few breeds have been identified to carry mushroom, Shetland Ponies, Haflingers and possibly American Quarter horse and Icelandic horses. Until recently, people assumed the color is silver on a black base, however genetic testing has proved surprising. It turns out that this coloration can actually be mushroom working on chestnut based animals. The effect of mushroom on black base is unknown.
The newness of this genetic discovery coupled with the fact it has been misidentified as silver for some time makes mushroom quite the mystery. Initially it looks like silver (or chocolate) dapple however mushroom animals are rarely dappled. Body color is various shades of sepia and mane and tail dilute even lighter. I was unable to find any images of mushroom animals in the public domain, but the Kellas Stud website has some great images and information about the genetics.
Finding good images to use for the color section has always been a challenge and we rely on public domain and creative commons which leaves us limited. If anyone has images of a mushroom animal they’d allow us to use we’d be happy to credit you for them and link to you in return. contact us if you are interested in sharing.