Chromate(5-), [6-(acetylamino)-4-hydroxy- 3-[(2-hydroxy-5-nitro-3-sulfophenyl)azo]-2-naphthalenesulfonato (4-)][4-hydroxy-6-[(2-hydroxy-5-methylpheny l)azo]-3-[(2-hydroxy-5-nitro-3-sulfophen yl)azo]-2-naphthalenesulfonato(4-)]-, potassium sodium