A look at sooty bay horses around the world and on a variety of different breeds.
The sooty modifier causes dark hairs to grow interspersed in the coat hairs, generally concentrated along the topline and points. This can create lovely counter shading and dappling on the body. Sooty on bay can be confused with yellow dun animals, which can also have dark shading on the shoulders and face. The obvious difference with a dun is that they will always have a dorsal stripe and bays do not. This modifier isn’t as drastic on a bay coat as it is on lighter animals like buckskin and palomino.