Benzenesulfonic acid,4-[4-[2-chloro-3-[4,5-dihydro-3-methyl-5-oxo-1-(4-sulfophenyl)-1H-pyrazol-4-ylidene]-1-propenyl]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]-,trisodium salt