Synonyms: 3H-INDOLIUM, 2-[5-[1,3-DIHYDRO-3,3-DIMETHYL-5-SULFO-1-(3-SULFOPROPYL)-2H-INDOL-2-YLIDENE]-1,3-PENTADIENYL]-3,3-DIMETHYL-5-SULFO-1-(3-SULFOPROPYL)-, INNER SALT, TRISODIUM SALT;TRISODIUM 2-((1E,3E)-5-[3,3-DIMETHYL-5-SULFONATO-1-(3-SULFONATOPROPYL)-1,3-DIHYDRO-2H-INDOL-2-YLIDENE]-1,3-PENTADIENYL)-3,3-DIMETHYL-1-(3-SULFONATOPROPYL)-3H-INDOLIUM-5-SULFONATE