The most common body colours found in the horse are black, brown, bay, chestnut and grey. However, apart from these common colours, there are myriad variations in colour which can exist in the horse. 

There is no uniform way to describe all the colours of the horse; there are major differences in colour description and nomenclature between Europe and North America, and in other cultures and language areas, colours may be classified and described completely differently.  

This chapter will give an overview of equine colours, and where possible a short note on the genetics behind the colours.

Seasonal variation in colours

Many colours can show seasonal variations which further complicate the precise description of a horse’s colour. This in part also explains why the colour is not such an important factor when identifying a horse – markings or an implanted microchip are more reliable ways of identifying a horse.

Associatio between breed and colour

• In certain breeds only a few colours occur and/or are officially recognised. The most prominent example of this is the thoroughbred, which is generally restricted to the basic colours
• Other breeds are known for their wide palette of colours with specialised terms for every nuance, prominent examples areIcelandic horses and Quarter horses
• In some breeds, a specific colour is a breed characteristic and no other colours exist within the breed, examples include Friesen horses, Haflingers and Fjord horses.

Colour pigments

In mammals, the hairs of the coat get their colour from pigment-building cells known as melanocytes that migrate across the body during embryonic development. Melanocytes produce two basic types of pigment known as melanin – red pigment (pheomelanin) and brown or black pigment (eumelanin). All colours are achieved through mixtures of these pigments combined with modifications that result in lightening or darkening of the overall effect. In extreme forms of modification, pigmentation is completely absent, resulting in a white horse (this is however not true albinism as it is seen in humans and other animals).

Original colour

The colours of ancestral horses differed according to their habitat, but they were generally shades of dun (either red or black).

The hair coat of a horse

For purposes of description, one differentiates between two different hair types:  

• The coat
• Mane and tail

Further reading: Chapter 'Skin' 

The coat

The coat is the hair covering the body, head and limbs – each primary hair of the coat is surrounded by a group of secondary ‘down’ hair. The two types are not necessarily of exactly the same shade of colour and this can lead to a difference in colour of a horse when it is clipped. 

Mane and tail

Mane and tail consist of coarser, thicker hair which grows much longer than the hair of the coat. Mane and tail serve as protection from insects.