Rosolic acid is primarily used as a pH indicator in various chemical and biological applications. It changes color in response to pH levels, making it valuable for detecting acidity or alkalinity in solutions. In microbiology, it is employed in culture media to differentiate bacterial species based on their metabolic activities. Additionally, it serves as a staining agent in histology to highlight specific tissue structures under microscopic examination. In industrial settings, rosolic acid is utilized in the synthesis of dyes and pigments due to its vivid color properties. It also finds application in analytical chemistry for the detection of metal ions, particularly aluminum and magnesium, through complexometric titrations.