Renowned for their deep shades and exceptional fastness, vat dyes are commonly used for denim and workwear textiles. However, their application traditionally involves high chemical input—particularly reducing agents like sodium hydrosulfite—and large volumes of rinse water. Sustainability advancements include the development of pre-reduced vat dyes and alternative reducing agents with lower toxicity and better biodegradability. These improvements not only reduce environmental risks but also allow for shorter dyeing cycles, lower temperatures, and more efficient water use. Modern vat dye formulations are also designed to work within integrated effluent treatment systems, facilitating compliance with wastewater discharge standards. As regulatory and brand pressures mount, sourcing platforms serve as critical tools in helping mills and brands identify high-performance, low-impact alternatives to conventional vat dye processes.