Oil Blue 35

Oil Blue 35 is a blue anthraquinone dye used for colouring alcoholic and hydrocarbon based solvents, including oils, fats, and waxes. It is used also in lacquers and inks. In some countries, it is used as a fuel dye. It is also used in some blue colored smoke formulations. In microscopy, it is used as a staining dye. When exposed to 5% hydrochloric acid solution, it becomes dirty green.