4-hydroxy-3-[(4-methoxy-2-sulphophenyl)azo]-6-[methyl[[2-(sulphooxy)ethyl]sulphonyl]amino]naphthalene-2-sulphonic acid, potassium sodium salt

4-Hydroxy-3-[(4-methoxy-2-sulfophenyl)azo]-6-[methyl[[2-(sulfooxy)ethyl]sulfonyl]amino]-2-naphthalenesulfonic acid/potassium/sodium,(1:x:x) salt