Used as a pH indicator in analytical chemistry, particularly in titrations involving weak acids and bases. It exhibits a clear color change in the pH range of 3.0 to 5.0, shifting from red to yellow, making it suitable for detecting endpoint in acid-base reactions. Also employed in dyeing textiles due to its strong affinity for cellulose fibers. Its chromogenic properties make it useful in some biological staining applications for microscopic examination of tissues.