2,7-Naphthalenedisulfonic acid, 4-amino-5-hydroxy-3-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, potassium sodium salt (1:?:?), coupled with diazotized 2-amino-4-[[4-chloro-6-[[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]amino]-1,3,5-triazin-2-yl]amino]benzenesulfonic acid