Used as a pH indicator in analytical chemistry, particularly in acid-base titrations. It exhibits a distinct color change around pH 8.2 to 10.0, shifting from yellow to blue, making it suitable for detecting the endpoint in weak acid-strong base reactions. Also employed in dye-sensitized solar cells as a chromophore due to its extended conjugation and ability to anchor onto metal oxide surfaces. Additionally, finds use in the formulation of certain photochromic materials and as a staining agent in some biological microscopy applications where pH sensitivity is required.