M'Bayar mare now OK

[Silverine]

Ohh man guys, sorry I should have seen this post!
I made 95% of all the M'Bayars out there haha ^^ It's a rather big herd, so I only take one picture after they have their most prominent adult features/reach breeding age.
The M'Bayar breed (as I have bred them) does not contain roan, champagne or any white markings. It does however contain a streak of quite heavy sootyness that appears in later adulthood. It can appear on both the back and the belly, sometimes just the legs, so that might also be it here

I'm going to put my two cents in and agree with Flyer-owl that the dark legs are almost definitely caused by the sooty gene. If they were caused by dun they would have shown up when Treasure was one-year-old, as that is when the full adult coat makes its appearance. After one year the only modifiers that will work on the coat are grey, sooty, and lp.

From what I can see, Treasure does not show any dun markings at all, and neither do either of her parents. Her sire is a bay and her dam is a brown. Neither has dun, therefore Treasure can not have dun. As Scythian said, Treasure's maternal granddam also has the darkened legs, but these are also caused by sooty rather than by the dun gene. As for Treasure's son being dun, his sire is dun and so he has an obvious source of it. Also went and looked up another apricot mare just to check that I wasn't missing anything. Without the sooty on the legs, Treasure would look exactly like this non-dun apricot:




Here is a lightly-expressed (and slightly sooty) apricot dun:



I also wanted to add that Adamant Blueblood actually does have very clear dun markings - while she doesn't have leg barring she does have a very dark dorsal stripe, a face mask on her muzzle, and very vivid demarcations on her legs between the upper leg diluted by the dun and the lower leg minus fetlock that has not been.

If you're looking for light dun expression, check out this stallion. It's nearly undetectable in most of his pictures but if you look very closely at his topline (especially at 3 years and 10 years) there is definitely a dorsal stripe. I have yet to find a dun that completely lacks a dorsal. The third post from the bottom on this page (post by Raikit) has links to a lot of lightly expressed duns.