The Sooty modifier acts on both red and black based horses by darkening the colour or certain areas of the horse. Sooty can cause dapples, it can cause individual black hairs, it can cause a darker shade along the topline and it can also darken the animal in a uniform manner.

• Sooty is most concentrated along the top of the horse, like a bucket of ash was poured from head to tail. 
• Sooty may express itself as a dark line, that varies in width, down the back of the horse. This is commonly mistaken for a dorsal stripe associated with Dun.
• It may be expressed by a dark shadow flowing onto the sides of the neck, over the shoulders and hips. 

The parts of the animal that are the least effected by Sooty are the areas underneath and soft parts, the flanks, behind the elbows, the buttock, the muzzle, around the eyes, along the belly and between the front and hind legs. (the opposite of "mealy" below)

Examples:

Needed