4-amino-6-[[4-[[4-[[4-anilino-2-hydroxyphenyl]azo]phenyl]amino]-3-sulphophenyl]azo]-5-hydroxy-3-[(4-nitrophenyl)azo]naphthalene-2,7-disulphonic acid, potassium salt

4-Amino-5-hydroxy-6-[[4-[[4-[[2-hydroxy-4-(phenylamino)phenyl]azo]phenyl]amino]-3-sulfophenyl]azo]-3-[(4-nitrophenyl)azo]-2,7-naphthalenedisulfonic acid/potassium,(1:x) salt