3-[[2,4-diamino-5-[[4-(4-nitro-2-sulphoanilino)phenyl]azo]phenyl]azo]-5-sulphosalicylic acid

3-[[2,4-Diamino-5-[[4-[(4-nitro-2-sulfophenyl)amino]phenyl]azo]phenyl]azo]-2-hydroxy-5-sulfobenzoic acid