Widely used as a dye in the formulation of automotive fuels, especially diesel, to differentiate between fuel types and for tax classification purposes. It helps authorities identify dyed fuels intended for off-road or agricultural use, preventing misuse in on-road vehicles where higher fuel taxes apply. Also used in some solvent-based ink and coating applications where strong red coloration is needed. Its stability in hydrocarbon solvents makes it suitable for industrial marking and tracer applications.