Modifiers

Grey, Roan, Pinto, and Appaloosa

Grey:  Contrary to popular belief, grey is not so much a color as a color modifier. Grey is a dominant gene that causes the horse's natural coat color, whether it be bay, black, dun, or palomino roan, to slowly "depigment" as the horse ages, much like human hair, regardless of the color, "greys out" with age. Most greys go through a lovely dappled phase, ending up nearly white or sometimes fleabitten. Because grey is a dominant gene, all grey horses will have at least one grey parent. Foals usually show evidence of greying on their faces first, particularly around the eyes. Also, the tip of the tail on most greys lightens up early on.

Pictured below is Holy Bull, exhibiting the changes in a grey goes through. Note how his face has already lightened in color even though the rest of his coat is still relatively dark in the photo on the left.


And here is Unbridled's Song, another grey who has not developed flea bites. There has been some speculation that fleabites were the result of either heterozygous or homozygous grey, but there doesn't seem to be much evidence to support it. Both Holy Bull and Unbridled's Song are heterozygous greys.


Some bay and chestnut based greys go through a phase called rose grey, like the horse above. Some rose greys dapple out and some, especially Arabians, tend to lighten up quickly without really dappling while still retaining a rosy hue.


An example of "grey goggles" on a bay foal who will go grey.

 

Roan: The roan gene acts by interspersing white hairs throughout a horse's coat, but the head, legs, mane, and tail remain "dark." Roan can act on any of the base colors as well as on any dilute or patterned color. For example, you could have a red roan (chestnut + roan), a strawberry roan (bay + roan), a blue roan (black + roan), or even a palomino roan (chestnut + cream + roan). Roan is often confused with grey, but it should be noted that roan horses look the same throughout their lives while grey horses fade out to nearly white (as seen above).

Chestnut Roan: Chestnut + Roan
The chestnut coat is sprinkled with white hairs except on the head, legs, mane, and tail. Sometimes called a red or strawberry roan.

Bay Roan: Bay + Roan
The bay coat is sprinkled with white hairs except on the head, legs, mane, and tail. Sometimes called a red or strawberry roan.

Black Roan: Black + Roan
The black coat is sprinkled with white hairs except on the head, legs, mane, and tail. Sometimes called a blue roan. (Pictured is Eddie Eyed Hancock, owned by Roans R Us.)

A bay roan foal. Notice how his head and points are dark right from birth.

A palomino roan (chestnut + cream + roan). Even with 2 different dilution genes at work, this horse's head and knees retain traces of the dark palomino color.

 


Pinto Patterns 

Pinto Patterns: Pinto is a term that refers to several different patterns of white. The patterns fall into two catagories, tobianos and overos. The overo catagory is really just a catch-all for non-tobiano patterns that includes frame overo, sabino, dominant white, and splash white. A horse with a combination of tobiano and one or more overo patterns is known as a tovero.

The tobiano pattern is dominant, and it is characterized by white crossing the horse's back between the withers and the dock, as well as by areas of color on the head, chest, and flanks. Most tobianos have normal face markings like stars and blazes, and they almost always have four white feet. The most minimally marked tobianos occasionally appear to have only 4 stockings and no other discernable white markings.

Frame overos are characterized by having a dark topline between the withers and dock, with blocks of white on their sides and necks. Frame overos usually have large blazes or apron markings.The feet are usually dark, but may be white if combined with other pinto patterns, particularly sabino. The frame gene is responsible for "lethal white overo." Horses that are homozygous for the pattern (2 copies) die shortly after birth. Heterozygous frames are perfectly viable. (See below.)

Sabino is a pattern that comes in many forms. In its minimal form, it only manifests itself as small socks and a star or blaze, if that. More extreme sabinos will have white patches, often with roaned edges, creeeping up their sides from the underside of the belly. The most extreme sabinos will look entirely white or nearly so, often retaining a few patches of color along their toplines, particularly on the ears or in the mane.

Dominant White is a pattern that was for a long time thought to be part of the sabino gene complex. Like sabino, the amount of white on the coat can vary, though most dominant white horses tend to be heavily patterned or nearly all white. Interestingly, dominant white is frequently found to be the result of a mutation, so loudly marked foals can result from otherwise plain parents. Like frame overo, dominant white is believed to be lethal in its homozygous state, but it is lethal early on in utero.

Splash white horses look as if they've literally been splashed with white paint from the underside or dipped in white paint. Splash white is an incomplete dominant. Homozygous spashes will have more white than heterozygous splashes. Splash markings tend to have smooth, crisp edges, and most splashes have blue eyes (especially the homozygous ones).

Most pinto patterns can range from minimal expressions (a nearly solid colored horse) to extreme expression (an all-white or nearly all-white horse). White horses resulting from tovero and sabino patterns are completely viable. White horses that are homozygous for frame overo, however, are known as lethal white overos (LWO). For more information on lethal white, please read my page about white horses.

Tobiano


A minimally marked black tobiano foal. Note the white across his withers indicative of the tobiano pattern.


This is Skip A Raindrop owned by Rocklyn Paints. She exhibits a minimal tobiano pattern as well---again, note the white patches on her withers and above her tail. Those prove she is a tobiano and not an overo, as the spot on her side might lead one to believe.


A typically marked tobiano---note the all white topline and the characteristic patches of color on the head, chest, and flanks. Tobianos frequently have spots with rounded edges. This horse probably carries sabino as well.


Another typically marked tobiano. The rounded edges of the pattern are very obvious on this horse. This one likely carries sabino as well.



This is The Eagle's Gift, a lovely tobiano Paint mare who exhibits cat tracks, the small spots on her shoulder. Cat tracks are often somewhat roany looking and are typical of homozygous tobianos. (Bred and photographed by Spotted Fawn Paints)

As I mentioned above, nearly all tobianos have 4 white feet. Occassionally, the pattern gets skewed, resulting in tobianos with dark feet like this guy. These skewed patterns are quite unusual and are usually only seen in Miniature Horses and Shetland Ponies.

 

Frame Overo


This is Buckeye WCF Shawnee Nightlight owned by BuckeyeWalnut Creek Farm. She shows a minimal overo pattern, characterized by the apron "blaze" or bald face.


This is Cupid's Snoopie Leo owned by Happy Trails. He is a typically marked frame overo with a wide blaze, spotting on his sides, and no socks.


Another lovely example of frame overo, this one with a bit more white due to the presence of sabino.


A filly owned by Painted Badlands Ranch who exhibits an extreme frame overo pattern combined with sabino. Note that her topline is still dark from the withers to the tail.

 

Sabino


This is Marquetry, a minimally marked sabino. Note the odd spot on his left front knee and white chin, typical sabino indicators.


This is Airdrie Apache, a more boldly marked sabino.


A sabino Paso Fino.



This elegant mare is Exotica, an extreme sabino (also called "sabino white") Paso Fino owned by Trademark Farms.



Dominant White


This handsome guy is Puchingui, sire of many modern dominant white TBs. Puchi is typical of moderately marked dominant whites.


This is The White Fox, who exhibits an extreme expression of the dominant white pattern. He is a son of Patchen Beauty and is part of that dominant white family that descends from KY Colonel and his daughter White Beauty.

 

Splash White


A minimally marked splash white. He is likely a heterozygous splash.


Another fairly minimally marked splash.


A very typically marked splash white Mini.

A more extremely marked splash white. Definitely a homozygous splash.

Tovero


This is Oroneeka, a Spanish Mustang exhibiting the tovero pattern, a combination of tobiano and frame overo.


This is an extreme variation of the tovero pattern known as Medecine Hat. The horse only retains color on it's flanks, around the eyes, and over the ears.


This is Designated Hitter, another tovero who exhibits the Medecine Hat pattern.

 


Appaloosa 

Appaloosa: The wild spotting pattern typified by the Appaloosa breed is caused by a group of genes called the leopard complex (Lp). The pattern can be manifested in several ways: varnish, blanket, leopard, snowcap, and few spot. Horses who are heterozygous (Lplp) for the leopard complex will exhibit the varnish, blanket, or leopard patterns. Horses who are homozygous (LpLp) for the leopard complex will exhibit the snowcap or few spot patterns. According to recent studies, the appaloosa pattern in it's heterozygous state seems to manifest itself similarly to the pinto genes. Moderately expressed appies will have a small blanket, more boldly marked horses will have larger blankets, and the most boldly patterned horses are entirely covered by the blanket, meaning they are leopard appaloosas. For more information on the ongoing project of mapping the appaloosa genome, please check out The Appaloosa Project. Appaloosa pattered horses also have distinct markings besides their spots---they have striped hooves, mottled skin, and white sclera.

A small blanket.

A larger blanket.

A larger blanket, sometimes called semi-leopard.

A leopard appaloosa.

Dudes Bonanza, a varnish roan appaloosa.

MTF Legacy's Red Baron, a snowcap with a small blanket. Notice the complete lack of spots, signifying his homozygosity.

Ima Starr Dancer, a snowcap with a larger blanket. Notice the complete lack of spots, signifying his homozygosity.

JR's Shado, a few spot appaloosa, also homozygous for the leopard complex.

 

On to Miscellaneous Modifiers

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