Color-shifting in Fjords

The lower legs of some Fjords have a muted color reminiscent of the color-shifted black pigment seen in some appaloosas.

From left to right: A color-shifted black (Eeaa) appaloosa, a bay dun Fjord, and a bay silver pony.

This blog started as a spin-off from my old studio blog. Because so much of my work in the equine collectibles industry was finish work  (coloring the sculptures), I would occasionally wander off into what I thought of as my hobby: horse color genetics. One of those early studio blog posts was about the color of my mare, Sprinkles.

The line down her back was a split in the blanket, not a dorsal stripe.

Sprinkles was interesting because, like many appaloosas, her base color was hard to categorize. Her previous owner called her grulla, perhaps because she mistook the thin split in her blanket as a dorsal stripe. (It also might have been wishful thinking, given how popular grulla was at the time.)

The vet who signed her Coggins papers called her chestnut. That made some sense. In bright sunlight, her lower legs could look somewhat reddish. To my artist’s eyes, though, that designation seemed wrong because the hue was off. The color looked too chocolate for liver chestnut, but too warm for silver-diluted black.

Sprinkles is pictured here at age two. Her leg color did not change with age.

I sent a sample for testing, and she came back as Eeaa: black. The only testable dilution at the time was cream, and she was negative for that. She was just black. As more tests became available, the result remained the same: no dilution.

I owned Sprinkles from the time she was two until she was in her mid-teens. She never looked black. In fact, while her pattern changed with age (slowly roaning), from season to season and year to year, her basic color stayed consistent. The only thing that changed it was the lighting. In bright light, she was a warm chocolate color. In low light, she looked cool and pewtery.

In low light, Sprinkles' coat lost its reddish tone. This was when her lower legs had a warm gray color.

I suspect the reason lighting mattered was that the hair on her lower legs was slightly reflective. Even when she was dirty, there was a sheen to it. It was one of those things that made me realize how important direct observation could be, because photos never fully captured it.

This is a good example of the sort of appaloosa I would have once assumed was a dusty shade of chestnut. Now, I would not be surprised to learn she is genetically black.

Sprinkles was what the Appaloosa Project called color-shifted black. As an artist, I was familiar with the dark pewter shade, which did not quite match any base color I knew. Being around a color-shifted horse made me realize just how far a genetically black horse could stray from what I might expect to see. It made me question some of the horses I would have previously assumed were some kind of chestnut. Despite their relatively pale shade, they had that odd combination of being slightly “off” in hue with a faint satin sheen.

So what does this have to do with Fjords? The appaloosa gene associated with color-shifting, Leopard Complex (Lp), isn’t present in that breed. Why would color-shifting be relevant?

For a while now, I’ve noticed that some Fjords have lower legs with a very similar tone to a color-shifted appaloosa. Although it is lighter in tone, the color is the same warm pewter. A few years ago, I was able to get some good close-up shots of a Fjord with these muted points.

These are all different angles of the lower legs of the same individual.

I didn’t have the chance to photograph this individual in natural light, or to set up a conformation shot. There are others like this out there, though. Some have points that appear paler than this.

I suspect that in the sunlight, this horse’s points would have less contrast with the rest of the leg. I say that based on what I have seen in conformation shots of Fjords with pale points.

 Here are some examples:

Herlig – bay dun but no test status given. His points are so pale that they are hard to distinguish from the rest of the leg.

Torheims Titan – bay dun with no cream. This stallion is very similar to the previous one.

Gjerde Trygve – bay dun with no cream. This one has only slightly more visible points than the previous horse

Viking Fjord – bay dun with no cream. Notice how pale and silvery his lower legs appear.

Søndre Ask – bay dun with no cream. This stallion has visible points, but they are more of a pewter hue.

In appaloosas, it is thought that color-shifting is caused by, or at least associated with, the Leopard Complex (Lp) gene. It is found with some regularity in appaloosas of all pattern types. That connection is not absolute, though. It is possible to find appaloosas – again, with just about any pattern – with fully black pigment. What makes one appaloosa have shifted black pigment while another does not is still an open question.

Although not color-shifted, this black dun Fjord shows an unusually pale body color. To get the bicolored mane, breeders have selected for pale, clear base colors.

What these Fjords illustrate is that other factors may produce a similar effect. Fjords have been selectively bred to highlight certain aspects of the dun coloring – like the pale guard hairs to either side of the mane – which have pushed the breed towards a lighter underlying color. Could one of those factors have this shifting as a side effect? Or was it something that arose in the Fjord population?

Now that Fjord horses are routinely color-tested and the preservation of the full range of colors in the breed has been prioritized, perhaps more research will be done into what makes their base colors unique.