42595, is a chloride salt of a dye with the chemical formula [C33H40N3]Cl.

Victoria blues are members of the triarylmethane dyes, but unlike most such dyes, the Victoria blues have a naphthylamine group.

[1] Victoria Blue BO is used to dye anionic substrates, e.g. wool, silk, nylon, and acrylics, where bright dying is required.

It is used to dye wool and silk directly producing a violet blue colour but cotton must be mordant with tannin.

Victoria blue BO is a photosensitizer.