Used as a moisture indicator in silica gel desiccants, where it changes color from blue (dry) to pink (hydrated), allowing visual monitoring of humidity levels. Commonly employed in electroplating baths to deposit cobalt metal coatings for wear and corrosion resistance. Serves as a catalyst in petroleum refining, particularly in hydrodesulfurization processes, and in the production of pigments for ceramics and glass, imparting deep blue colors. Utilized in the synthesis of other cobalt salts and coordination compounds. Also found in some drying agents for paints and varnishes due to its hygroscopic nature. In laboratory settings, it is used to detect water content in organic solvents through color change.