Regular chlorine bleach generally lightens colors or brightens whites when it comes to doing the laundry, but color-safe bleach behaves a bit differently. A color-safe bleach is made from a different chemical than a standard bleach, which makes it safe to use with most fabrics that can be laundered with regular laundry detergents.
Beyond the Basics
The active ingredient in standard bleach is sodium hypochlorite. This substance, if spilled on a dark cotton shirt, for instance, may remove the dye from the shirt, leaving behind a light spot. Color-safe bleach uses hydrogen peroxide instead of sodium hypocholorite. While peroxide is a bleaching agent, it doesn't affect the dyes in many types of fabrics, so it won't change the fabric's color. If unsure whether your colorful clothing or other fabrics will hold up to a color-safe bleach, test it by pouring a small amount of the color-safe bleach on an inconspicuous area of the fabric and let it sit for 30 minutes or so before rinsing it out.