Victoria blue B is an iminium salt composed of 4-{(4-anilinonaphthalen-1-yl)[4-(dimethylamino)phenyl]methylidene}-N,N-dimethylcyclohexa-2,5-dien-1-iminium and chloride ions in a 1:1 ratio.
Victoria blue B is a dark purple cationic dye from the group of triphenylmethane dyes that dissolves in water with a blue color.It can be produced by condensation of Michler's ketone with N-phenyl-1-naphthylamine.