Immature birds are brown with white dappling and have greenish blue-grey facial skin. Firstly, academics have highlighted the risk of dappling statute of frauds and other requirements. Some bay horses exhibit "dappling," which is caused by textured, concentric rings within the coat. Sootiness can be minor or quite extensive, and often includes dappling. The coat may also exhibit reverse dappling, though this is also an unreliable indicator.