Color fastness measures a fabric's resistance to fading or bleeding during washing, rubbing, light exposure, and perspiration. Poor fastness releases dyes and heavy metals, posing skin health risks and staining other garments. This guide covers essential tests (ISO, AATCC, JIS compliant), required equipment (e.g., GESTER washers, crockmeters, light testers), and industry standards for textiles like apparel, upholstery, and technical fabrics. Discover how proper testing ensures product safety, du