2-[2-[2-Chloro-3-[(1,3-dihydro-1,3,3-trimethyl-5-sulfo-2H-indol-2-ylidene)ethylidene]-1-cyclohexen-1-yl]ethenyl]-1,3,3-trimethyl-5-sulfo-3H-indolium inner salt sodium salt
2-[2-[2-Chloro-3-[(1,3-dihydro-1,3,3-trimethyl-5-sulfo-2H-indol-2-ylidene)ethylidene]-1-cyclohexen-1-yl]ethenyl]-1,3,3-trimethyl-5-sulfo-3H-indolium inner salt sodium salt