Horse Coat Color Modifiers There are several different modifying genes which can have an effect on coat color. Grey Modifier Learn more about the grey modifier Bay Modifier Learn more about the bay modifier Seal Brown Modifier Learn more about the seal brown modifier Mealy or Pangare Modifier Learn more about the Mealy/ Pangare modifier Sooty or Smutty Modifier Learn more about the sooty/ smutty modifier Flaxen Modifier Learn more about the flaxen modifier Colors | Base | Modifiers | Dilutions | White Patterns | Rare | Markings