Break Out of Your Hair Rut

Your Hair Color-opedia

Used to cover gray or to go from one shade to another (say, blond to brunet, or vice versa), permanent color contains ammonia and peroxide to deposit long-lasting pigments deep within the hair shaft. You'll need to touch up roots in four to six weeks.

Contains tiny molecules of dye that coat the hair's outer cuticle and rinse away after several shampoos. Since it contains no ammonia or peroxide, semipermanent color can only brighten or darken existing color, not change it, and is gentler on hair than other methods.

Swells the hair's outer cuticle, allowing dye to penetrate.

Permanently traps in color molecules.