4-(alpha-(p-(diethylamino)phenyl)-(2,5-disulfobenzylidene)-2,5-cyclohexadien-1-ylidene)diethylammonium hydroxide inner salt, sodium salt
N-[4-[(4-(diethylamino)phenyl)(2,5-disulfophenyl)methylene]-2,5-cyclohexadien-1-ylidene]-N-ethyl-ethanaminium hydroxide