Used as a dye in automotive fuels, particularly diesel and heating oils, to differentiate taxed and untaxed fuel types. Enables authorities to detect illegal use of low-tax or tax-exempt fuels in on-road vehicles. Also serves as a colorant in solvent-based systems and lubricants where strong red tinting is required. Exhibits good solubility in hydrocarbon solvents and maintains color stability under normal storage and operating conditions.