 The gray gene does not affect skin or eye color, so grays typically have dark skin and eyes, as opposed to the unpigmented pink skin of true white horses.The skin and eyes may be other colors if influenced by other factors such as white markings, certain white spotting patterns or dilution genes.Gray foals may be born any color, but the colored hairs of their coat become progressively silvered as they age, eventually giving mature gray horses a white or nearly-white hair coat.