Bay is a hair coat color of horses, characterized by a brown body color with a black mane, tail, ear edges, and lower legs. Bay is one of the most common coat colors in many horse breeds.

The pigment in a bay horse's coat, regardless of shade, is rich and fully saturated. This makes bays particularly lustrous in the sun if properly cared for. Some bay horses exhibit dappling, which is caused by textured, concentric rings within the coat. Dapples on a bay horse suggest good condition and care, though many well-cared for horses never dapple. The tendency to dapple may also be, to some extent, genetic.

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