The ADMS (Donkey Registry) is trying to change the term used to describe the grayish-visual coloration in donkeys. In earlier times, the term "Gray-dun" was used. The reasoning was that most people would look at a donkey and say “it’s gray,” and secondly that it was believed to be a form of dun (due to the fact that many had darker heads plus a cross and stripe ~ a definate dun factor in horses). But now as research progresses, logic dictates that this particular coloration may NOT be a true dun. A true dun is a type of dilution color – lightening the body color, while leaving the extremities (head, legs) alone.

So, why don’t we just call it GRAY and be done with it? One reason is that "Gray" happens to be a HORSE term. It is also a specific term that has been in use for hundreds of years. There are other examples of using GRAY in the animal kingdom (which includes man) which we will cite.

GRAY in horses is actually defined as an animal which is born dark, but whose entire haircoat gradually changes to white. It is more properly termed GRAYING or AGING GRAY, but if you see a white horse (with dark skin), he is really a GRAY. The term is really chopped and shortened for a process, and gives no thought to the original darker color, which can be interesting when genetics are mapped. There are some terms for stages of the GRAYING process – "Steel gray" if they are a dark blue, "Rose gray" if a bay or chestnut is graying out and has mixed red & white hairs, "Dapple gray" if the lighter color dapples appear in the coat. Additionally, there is also "Fleabitten gray" (white with darker, usually red, hairs sprinkled throughout), and almost pure-white (the advanced stage) "Grays."

Face it, GRAY is a variable – or changing – color. A GRAY horse will always have one GRAY parent. GRAY can be a "homozygous" gene (meaning both parents were gray and the offspring has 2 doses of the gray gene, one from each parent) or "heterozygous" (just one gray gene). GRAY only requires one dose of the gene to cause the coat to lighten over the horse’s life.

So, DONKEYS that look “gray” to the average individual are stuck in a definition war. GRAYING is a better term for the horse color (but don’t look for it ever to be changed!) , since it implies the changing process. The “Gray” that donkeys show is more like a pigment – a fixed shade of gray. Think of your grandma’s hair going all white – didn’t she say she and grandpa were going gray? The majority of donkeys that are the familiar blue-ish gray shade will never turn white. That’s because the donkey color is not the same as horse GRAY. That’s why it shouldn’t be called GRAY. Sorry, but the horse people used the term and incorporated it into regular usage first.

GRAY as a PIGMENT – like a paint – is obviously a “Fixed” color. This means it won’t change. A "Gray” crayon on paper will stay the same shade of GRAY. But remember that a GRAY crayon used both black and white mixed together to get that shade. On a donkey’s coat, the shade is caused by each hair being the blue-gray color, not a mix of black hairs and white.

This is why the ADMS proposed the new term, "SLATE GRAY." The closest coloration in horses is GRULLA (Grullo). Each hair is individually a blue-gray color. The term GRULLA actually means “crane” in Spanish. And as you know, the crane is a blue-ish gray color. So SLATE GRAY, slate-blue, blue, crane, mouse, grulla, grullo, blue dun – all are describing the blue-ish gray color that stays blue-ish gray and never turns white.

If a donkey is a visual shade of gray (blue, mouse, crane, grulla) then SLATE is the base color. Yes, it can be brownish, or reddish, or may have some white hairs mixed in. But each individual hair is mouse-colored, not an overall mix of black and white to produce a gray look.

ROAN is when some white hairs are mixed into the coat. The terms ROAN and GRAY are use interchangeably by some people and by some registries. Here is how they really differ: The Roan horse may have some seasonal variation, but will retain the darker portions of the coat all year. Most roans have dark heads and legs. They will stay throughout the horse’s life. A GRAY horse will start to gray-out on the head first, and the whole body will eventually lighten – more and more each year. ROAN is seasonal, but stable. GRAY is progressive, and will always get lighter.

Some ROANING on a donkey is not uncommon. It is seen frequently in sorrels, in some blacks, and on slates, and is very common on larger donkeys. There are differences between ROAN in donkeys and in horses, but for the purpose of definition, Roan is SOME white mixed in, GRAY is progressing.

SLATE GRAY is a dominant olor. It can hide the other colors that are recessives. Here is a scenario: You breed a SLATE GRAY to a sorrel. The resulting jennet foal is SLATE GRAY. But using your knowledge of equine genetics, you know that sorrel is recessive, and the jennet foal is carrying one SLATE GRAY and one SORREL gene. You breed her to a sorrel, you have a chance of sorrel, rose dun, or slate gray foals. Breed her to a black/brown jack, and depending on the jack’s background, you should get slate, dark brown, or perhaps black or sorrel. Even though some foals are slate gray, they will carry the recessive for the darker genes.

You can call the colors anything you want, but using an agreed set of terms is always best. That’s why we don’t use the term chocolate – Hershey’s or 3 Muskateers? Special Dark or Kit-Kat? Yes, there is overlap in the colors. Yes, not everyone will always agree on the exact shade. This is not the important part. No one, in all horse registries, in donkey registries, in animal registries anywhere will ever completely agree on terms.

A red-all-over Quarter Horse can be a sorrel or a chestnut. Some say the difference between sorrel and chestnut is the shading on the body. Some used to say the color of the mane and tail made the difference. The same red Arabian is a Chestnut. The term sorrel is not used for Arabians. Conversely, the same red color in a Suffolk Punch draft horse is always a sorrel. They don’t use Chestnut as a color. Confusing? You bet. Will it change? Probably not.

There is a coloration in donkeys which looks something like the AGING GRAY in horses, but to stay away from the confusing, it is termed FROSTY in donkeys. FROSTY may progress a little, FROSTED is grayed or roaned (we are not sure at this time which it is genetically) out more completely.

Horses GRAY out, and become white. It’s a common color. Donkeys are SLATE GRAY and stay the same rich blue-gray their entire life. So you see, the colorations are different. The terms are different. Call them whatever you like, Mxlpxl, crane, mouse, blue, make up your own terms. They are not AGING GRAY, and should not be confused with the horse coloration. They should also be evaluated on their own merit and not be condemned for being the ancestral and dominant color of the donkey species.

(This Page last updated: February 15, 2002)