sodium [3-[4,5-dihydro-4-[(2-hydroxy-5-nitrophenyl)azo]-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonamidato(2-)][4-hydroxy-3-[(2-hydroxy-1-naphthyl)azo]benzenesulphonamidato(2-)]chromate(1-)