2,7-Naphthalenedisulfonic acid, 4,5-dihydroxy-3-(1-naphthalenylazo)-, disodium salt 5850-63-5 Amacid Chrome Blue 3B C.I. 16640 C.I. Acid Violet 13, disodium salt Chromotrope 10B NSC45208 Pontacyl Violet 6R Wool Violet 2R