Widely used as a purple dye in textiles and paper industries for coloring. Commonly employed in microbiology as a staining agent in Gram staining to differentiate bacterial types. Acts as an antifungal and antiparasitic agent in aquaculture, particularly for treating fish eggs. Used in some ink formulations for writing and printing. Also applied in histology for cell visualization and in some diagnostic tests as a pH indicator. Has been used traditionally in some regions for topical antiseptic purposes, though this is limited due to potential toxicity.