Direct Blue 15

COC1=C (C=CC (=C1) C2=CC (=C (C=C2) N=NC3=C (C4=C (C=C (C=C4C=C3S (=O) (=O) [O-]) S (=O) (=O) [O-]) N) O) OC) N=NC5=C (C6=C (C=C (C=C6C=C5S (=O) (=O) [O-]) S (=O) (=O) [O-]) N) O.[Na+].[Na+].[Na+].[Na+]