Grey Horse Color – Why Do Some Horses Turn Grey?

Last Updated on January 26, 2022

The grey horse color includes a wide range of different types of grey horses. These range from a completely white coat color through to a dark, steely grey. But why do some horses turn a grey color?

Why Do Some Horses Turn Grey?

The coat color of horses occurs because of their genetic makeup. Each horse inherits genes from its parents; these genes are paired, and the horse gets one of each pair from each parent. It is the combination of genes within these pairs that determines the color and markings of the horse.

The basic color of a horse is a result of whether it inherits two black genes, two red genes, or one of each. This results in a base color of either black, chestnut, or bay. These three common horse colors are then affected by other genes, which creates the myriad of colors and patterns we see in the equine world.

Why Do Some Horses Turn Grey

Other color-changing genes include dilution genes, that lighten the overall color of the horse. Some horses also inherit the grey gene from their dam, sire, or both. The grey gene causes gradual depigmentation of the hair, over several years, resulting in a grey horse color.

This is an unusual gene, as it is not always clear when a foal is born if it carries the grey gene or not. This means that a foal might be born a bright bay, or a golden chestnut, or even jet black, but within a few years, it could be completely white!

The gene responsible for hair turning grey is dominant over all other color genes. This means that it will overrule all other genes responsible for coloring, and the horse will inevitably turn grey. This occurs whether the horse has one or two copies of the grey gene.

Check Out Types Of Roan Horses And Colors Explained

How Do Horses Turn Grey?

Horses turn grey in stages, and there is no set time frame in which this occurs. It is normal for a grey horse to exhibit predominantly grey coloring by the time it is an adult. However, the coat will continue to lighten over time, and by the time a grey horse reaches its geriatric years, it will be almost white.

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Here is a summary of the stages of the greying process in horses:

  • Foal

The foal will not normally have any grey hairs at birth, but a foal of any color can turn grey. This can lead to confusion in the horse’s passport, where its color at birth is normally recorded. When the foal sheds its birth coat during the first year of life, it may develop some grey hairs.

  • Intermediate Stage

As the horse moves through adolescence, the coat will become lighter. This is because white hairs are becoming more prevalent, and intermingling with colored hairs. For example, a black horse will have an even number of black and white hairs, resulting in a steel or iron grey color.

At this stage, the horse might also develop a spotted appearance, called dappled grey.

This intermediate stage is often confused with other colorings, such as roan. However, a grey horse will continue to become lighter, whereas a roan will stay the same color. Roan horses also have darker-colored legs, whereas a grey horse will normally develop lighter legs.

  • Late Stage

A grey horse does not normally become lighter evenly across the whole body. The flanks and the legs normally retain some color during this stage, whilst the other areas become lighter.

  • Complete Depigmentation

This is the final stage of greying, where the horse is almost completely white. Many horses stay this color, whilst others develop small pigmented freckles, called flea-bitten grey. The skin of a grey horse remains black, even when the coat is pure white.


So, as we have learned, the gene that causes a grey horse color is very dominant and will overrule all other color genes. However, most horses are not born grey and will turn grey gradually over a number of years. This is because the grey color gene causes the hairs of the coat to gradually lose pigmentation.

We’d love to hear your thoughts on the grey horse color! Maybe a steely dapple grey is one of your favorite horse colors? Or perhaps you’re not sure if your new foal is going to be grey or not? Leave a comment below and we’ll get back to you!


What Is A Grey Horse Color Called?

Many people look at a horse with white hair and think it should be called a white horse! But, as with many things in the horse world, it is not quite as straightforward as this. A horse with hair color ranging from steel grey to pure white is normally called a grey, regardless of shade.
For a horse to be truly classed as a grey color, it will have dark skin and eyes. This is because a grey horse is one that is born any color, and the coat loses pigmentation as the horse ages. This differs from other genes with hair lightening effects, which often also change the color of the skin or eyes.

What Are The Different Types Of Grey Horses?

The color of a grey horse changes throughout its lifetime, so you will see many different types of grey horses. This is because the gene responsible for grey coloring causes gradual depigmentation of the hair, so the coat color will gradually fade over a period of several years.
The different types of grey horses also depends on whether they have one or two copies of the grey gene. The grey gene is always dominant over other coat colors, but if a horse has inherited it from both parents then the effects will be much stronger.
So, a horse with one copy of the grey gene may turn grey at a slower rate, or more unevenly. This can lead to coat colorings such as a fleabitten or dapple grey.

What Color Is A Dapple Grey Horse?

In some grey horses, a pattern will form on the coat called dapple grey. The overall color of the coat at this stage is dark grey, interspersed with lighter grey rings.
This is an intermediate stage of the greying process in horses and is very attractive. However, even a dapple grey horse will turn almost completely white eventually.