(3)        The Gray coating:  gray means lighter black.  It is usually developed from darkening white coating, and may also appear with yellow coating simultaneously.  It indicates interior syndrome.  Often seen in heat or cold syndrome.  A gray but dry fur shows the reduction of fluid because excessive heat, usually indicates exterior heat; or deficiency in Yin with hyperactive fire usually observed in miscellaneous internal injuries.  Gray but moist fur is often seen in stagnating phlegm and fluid, or stagnating cold dampness.