Color fastness is a term used in dyeing of textile materials means resistance of color to fading, i.e. it refers to the notion of an object having color that retains its original hue without fading or running. The term is usually used in the context of clothes. The first known use of the word colorfast was in 1916.In general, clothing should be tested for colorfastness before one uses bleach, or another type of strong cleaning product. Light fastness, wash fastness, and rub fastness are the main ones that standardized. The light fastness of textile dye is categorized from one to eight and the wash fastness from one to five. The higher the number the better fastness is obtained.
Definition of Colorfastness
Definition: Clothing is colorfast if its colors and dyes do not bleed or run from the clothing. Clothing should be tested for colorfastness before using any type of bleach or bleaching solution, or strong cleaning product.
How to Test
To test for colorfastness, find a hidden seam of the garment or a hidden spot. Apply the cleaner to the garment and then dab the area with a clean cotton cloth. If the color removes itself from the garment onto the cloth, you should not use the cleaning product on the clothing.