Used primarily as a hair dye ingredient, this compound provides blue to violet shades in permanent and semi-permanent hair coloring formulations. It is valued for its ability to produce vibrant cool tones and correct brassy or yellow undertones in lightened hair. Commonly found in professional and consumer hair dye products, it works through oxidative coupling with other dye precursors to develop stable, long-lasting color within the hair shaft. Its application is typically combined with developers like hydrogen peroxide to achieve the desired shade intensity and coverage.