Dun on Bay

Dun on Chestnut

Dun on Black

Dun is a lightening of the coat visible everywhere except the horse's lower legs and face.
It also causes "primitive markings": horizontal barring on the hocks/knees and a stripe down the spine.
Barring across the dorsal stripe may also be present at the withers.
Dun markings may also create dark tips on the ears and "spider webbing" on the forehead, which can go no lower on the face than the eyes. 

Primitive markings and legs should be slightly darker than the base coat, or black if the points are black.
In Bay-based coats (E_ A_), it is permitted to darken the face to the same color as the legs.

Genotype: D_
Locus:  Not shared with any known genes

• Coat: Lightening of the coat except for the lower legs and face.
• Mane and Tail: Not affected, except that "guard hairs" or small light-colored or white hairs may be present at the roots.
• Skin: Not affected.
• Eyes: Not affected.
• Hooves: Not affected.

Range:

• Minimum: Visible barring on the hocks and knees and a visible dorsal stripe.
• Maximum: Visible lightening of the base coat and extreme primitive markings (barring at the withers, legs, forehead, ears) and guard hairs on the mane and tail. Wither barring should present as no more than 3 parallel stripes (all going the same direction) and should be no wider than the scapula/shoulderblade.

Interactions:

• Chestnut: When Dun is on a Chestnut base coat, the phenotype will read "Red Dun."
• Black: When Dun is on a Black base coat, the phenotype will read "Grullo."