The use of henna to dye the legs of horses is traditional in some countries and disciplines.
Recently some photos were shared on social media of a grey horse with red legs. It would be easy to dismiss this as yet another photoshop trick, but I encountered two similar horses at the 2018 World Equestrian Games. That was where I learned that in Endurance, some competitors apply henna to the legs of pale-colored (usually grey) horses.
I had seen henna-dyed horses in Persian and Indian miniature paintings like the one pictured below. By the frequency that the markings are depicted, the practice must have been very common. Until I saw the horses at the Games, I did not know it was still done.
The resulting color on the two horses was quite different. The first one was a very unnatural yellow-orange. The color on the legs of the second horse, however, could be mistaken for vivid red chestnut. I have to admit, though, that if I hadn’t personally taken these photos, I would not be able to tell if the images had been photoshopped. (The odd way the yellow-orange registered with my camera makes that top image look especially questionable!)
The tonal shifts – like the dark area on the back of the hocks – looked surprisingly natural on the second horse.
Artificial coloring is one of those things you don’t necessarily think of when looking at a horse’s color. For many years I wondered at the tendency of sabino Tennessee Walking Horses to retain their dark legs until I noticed that the number of white feet on winning stallions increased once their shoes were pulled. A trainer later told me that it was common to black the front legs – most sabino Walkers are black – so they blend into the black built-up shoes. Owners sometimes tattoo the pink skin around blue eyes, believing it helps to protect them from the sun. Tails are sometimes dyed to make a tail extension less conspicuous. It is not something that comes up often in horse color, but taking human actions into account can sometimes give answers about unexpected colors.