What Is Colorfastness?

A fabric's resistance to fading or bleeding color during washing, light exposure, or rubbing.

Colorfastness measures how well a dyed fabric resists fading or transferring color under washing, light exposure, or rubbing (crocking). It's tested as part of OEKO-TEX and standard fabric quality checks, and it matters especially for darker and more saturated shades, where dye transfer onto skin or lighter garments during wear is one of the more common post-shipment complaints from end customers if not properly tested before bulk production.