This post first appeared on March 8, 2012
One of the things that used to stump me, when I first began painting horses, was the base color on many of the Appaloosas. Often the horses had an odd pewter brown coloring that did not look quite like chestnut – not even liver chestnut – and was not really black. Many years later, I found myself owning just such a horse. The picture above is my mare, Sprinkles. In that particular picture, she is three years old. If you look closely, you can see that her lower legs are a bronze color. In bright sunlight, that is the best term for her coloring. In lower light, and when she is in her winter coat, she is closer to a dull pewter.

Her previous owners thought she was a grulla, probably because they mistook the split in her blanket for a dorsal stripe. I also wonder if they weren’t subconsciously seeing what seemed pretty clear to me, which was that the tones in her coat were all wrong for even the dullest red-pigmented horse. She looked like a diluted black horse of some kind.

And that is exactly what her tests from UC Davis showed her to be. She is genetically black (Eeaa) without any known dilution gene. Her coloring isn’t the result of sun-fading. Most blacks that sun-fade retain a certain amount of darker pigment on their lower legs. Her lower legs are the palest tones on her body. This photo was taken last summer, when she was eight years old. The lighter area at the top of her leg is appaloosa-related roaning. Although there are a few white spots on her legs (none visible in this shot), there are no roan hairs below her knees. The hair itself is lighter and somewhat iridescent.

When I got her results back in 2008, I posted a series of comparison photos on my studio blog to show how the tones on lower legs differed. This is the sort of thing that artists need to be able to see in order to capture different colors in a believable way. It’s also something that artistically inclined people tend to do well, which is probably why many artists are good at guessing color when tests are not available.

I’ll give the same caveat about these photos that I did when I first posted them. Photographs are not the best way to really see these differences, even for people that are good at noticing them. All the ways we record and transmit images (film, printing, monitors) can distort color, and with something like this what we are dealing with are very subtle differences in tone. These images were taken with the same equipment in close proximity to one another, but still viewing these colors in real life – preferrably side-by-side – is the best way to see. Indeed, the tone in color is really best studied from life because the camera rarely captures what is so obvious in person. But this is as close as we can get over the internet!

These are the legs of a sooty palomino pony. Notice how yellow in tone the lightest areas are. “Yellowness” is one of the best indicators for the presence of the cream gene.

These are the legs of a red silver pony. This horse is genetically bay, and you can see the unaltered red hairs on the upper leg. His black lower leg has been diluted by the silver gene, turning it a bluish chocolate. The overall tone on the lower legs is very cool, especially compared to the yellow of the palomino above.

And these are Sprinkle’s legs. Again, she’s genetically black so like the silver legs above, this is a diluted form of black. The color isn’t cool, however. It isn’t yellow, but it’s not really red either. If I had to call it something, I would say it is a bronze tone.

Here is a side-by-side comparison of the leg color, with an addition of a sooty chestnut to compare against a truly red leg.  (The image links to a much larger version.)

And finally here are bronzed legs beside a flaxen chestnut leg and a truly black leg, showing the contrasting tones.

To my knowledge, no formal studies have been done to determine what causes this. It does not happen to all black appaloosas, but it is not especially rare either. Tomorrow I will post a few more examples.