Disperse Red 9, also called C.I. 60505 and 1-methylamino anthraquinone, is a red dye derived from anthraquinone. Disperse Red 9 is used in some older red and violet-red colored smoke formulations. It is used in the M18 colored smoke grenade and also often in dye packs. Its properties can be improved by coating the dye particles with an inert material, e.g. an epoxy resin.