The Equine Rainbow

 

The Equine Rainbow: A Crash Course in Colour Genetics

This is a *very* basic colour guide for the breeders of the Kalidorian Unicorns. If you would like more indepth information, I recommend these websites:

Equine Color Geneticshttp://www.whitehorseproductions.com/ecg_basics1.html
Foal Color Calculatorhttp://www.animalgenetics.us/CCalculator1.asp

Little Foghorn

Basic Horse Colour:

A Horse’s coat comes in two colour pigmentsRed (Chestnut) and Black. Chestnut can range in shade from rich chocolate to copper-penny red to flaxen; black is the stately dark colour of coal. Chestnut is the most recessive colour, and Black is the second most recessive colour. What this means in breeding terms is that if you breed two chestnuts together, you will always get chestnut; if you breed two blacks together, you will always get black or chestnut. These two colours are the base for every other colour you might see on a horse.

Black, and some of the Many Shades of Chestnut:

Colour Modifier:

What changes chestnut and black into all the shades of the equine rainbow are modifiers. Some modifying genes are refereed to as “dilutions”, because they dilute the colour they affect.

It’s important to note that you can have several different colour modifiers working on a horse at once; this can lead to some pretty interesting colour combinations!

Bay is the most common dilutions; it is also the original “wild” colour of the horse. Bay works to limit black pigment on the body so that only the legs, mane/tail, ears and nose remain dark. The base colour of bay ranges in all shades, just like chestnut, from very dark mahogany to bright bay. If you breed a bay to a black or chestnut, you could get any of those three colours on the foal.

Common Dilution Colours:

  • Cream – works on red to fade the colour to light golden colours, but has limited effect on black; a double-dose of cream results in an even lighter colour. Cream is probably one of the most popular and easily recognized dilution!
    • Chestnut + Cream = Palomino (x2 cream = Cremello w blue eyes)
    • Bay + Cream = Buckskin (x2 cream = Perlino w blue eyes)
    • Black + Cream = Smokey Black (x2 cream = Smokey Cream w blue eyes)

    From left to right, Palomino & Cremello; Buckskin & Perlino;

 

Smokey Black (which is often indistinquishable from standard black!) & Smokey Cream:

  • Dun – similar to bay, but works on both base colours and produces “primitive’ markings – dorsal stripes, leg-baring, and face masks.
    Classic (Bay) Dun, Red (Chestnut) Dun, Grulla (Black Dun):
     
     

  • Silver – fades out black, limited effect on chestnut. They are also called “Silver Dapple” because this colour can produce an amazingly distinct dappled effect, too. Silver horses are often mistake for chestnut because they will have light-coloured manes & tails.
    Silver “Dapple” (Black), Silver Bay, and teamed up with black dun for Silver Dun (Grulla)
     

  • Champagne – similar affect to cream, but works on both base colours. Champagnes have pink skin and are also known for their shiny, metallic-looking coats and striking green or amber-coloured eyes.
    Amber (bay), Golden (chestnut), Ivory (Cream), Classic (black)
     

Patterns in White

White markings on horse – everything from a tiny star on the forehead to a wild appaloosa pattern – are controlled by another set of modifying genes. These genes act separately to control where white appears on a horse, regardless of base colour. With each pattern, the result on a horse can range from minimal – barely noticeable and often over-looked, to loud – which means lots of white – even a completely white horse!

The Paint Horse
“Pinto” or “Paint” refers to a horse with broken patterns of colour and white. There are several separate genes that control how this patterns looks, so I’ll only deal with the most common ones. The patterns are not interchangeable (meaning, you can’t breed horses of one pattern type and expect to get another) but like dilutions, you can have more then one pattern working on the same horse; for instance, it is the combination of tobiano with either sabino or overo can produces the popular “medicine cap” pattern.

  • Sabino – recognized by high stockings, belly splotches, and wide blazes that wrap under the chin. Occasionally, sabino can cause flecking that mimics roan or produce “all white” individuals. Clydesdale horses are iconic sabino.
  • Tobiano – recognized by white patches that tend to run vertically across the back of the horse, and is responsible for the common “shield” pattern seen on gypsy cart horses.
  • Overo – recognized by white patches that tend to run horizontally across the horse, not crossing the back. The famous horse from the movie “Hidalgo” was an overo.
  • Splash – recognized by white that looks as if the horse has been “dipped” in white paint from the bottom up. One of the rarer paint patterns.

Sabino, Tobiano, Overo & Splash:

Appaloosa Complex
The appaloosa horse may have any arrangement of spotted patterns, from a small tidy blankets to wild leopard spots, to nearly white no-spot appies. All appaloosa have striped hooves and speckled skin, and can throw any number of patterns on its babies. It’s also not uncommon for a foal’s pattern to change and grow over time, thus, it’s often very exciting to wait and see just what kind of appaloosa your foal turns out to be!

The common appaloosa pattern are:

  • Blanket – lacey white patch extending from rump with various spots within
  • Leopard – white with “dalmatian” spots all over
  • Varnish Roan – silvery hairs through-out body, with or without spots
  • Snowcap – solid white patch extending from rump wich may or may not have spots
  • Few Spot – mostly white horse with dark mottling, especially around the eyes and soft parts
  • Frost/Snowflake – a fine dusting or splattered white specks all over

A Bay Blanket, Black Leopard, Chestnut Varnish, Palomino Snowcap,  Liver Chestnut Frost, Black Few-Spot


Roan
Roan is a thorough white flecking throughout body except for the extremities; a roan’s head and legs remain dark, as do the mane and tail. Often roans will develop dark spots throughout their coat as they age, called “corn spots”.

Blue Roan (Black), Red Roan (Bay), Strawberry Roan (Chestnut)
A Note on Rabicano – a rather uncommon pattern but no less stunning, a rabicano tends to have white hairs in two places – on the flank, often forming vertical bars, and streaked at the base of the tail, often referred to as a “skunk” or “coon tail”.
All About Grey

Grey was the first colour to be studied in the new science of equine colour hereditary; grey doesn’t hide or skip generation like some other colours – a grey horse must have a grey parent. Grey is also a “great” colour for hiding whatever colour might be underneath – which is why it’s not popular in colour breeds such as appaloosas or paints. It can work on top of any shade and fades it out slowly over time, turning white with age. Some horses grey very quickly, some very slowly. And even though these horses may appear pure white, they are always still referred to as “greys”.

Depending on the colour the horse was originally, you can get some lovely shades of warm grey: Chestnut-going-grey can produce some lovely Mulberry Greys, and Bay-going-grey gives the best Rose Grey. Dappling is also common with grey horses, but not exclusive. Flea-bitten Grey occurs with flecks of the original base coat freckle the entire horse; flea-bites are also responsible for the famous “bloody shoulder” marking in Arabian legends.

Shades of Grey: Dapple, Steel, Light (White), Rose, and Mulberry Grey:
Of course, every grey horse ends up “white” in the end!
Thanks for reading, more colour information will be added as needed!

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