Our color of hair is contributed by melanin that bind in cortex of our hair. Our keratin without melanin is yellow pale in color. Bleaching uses oxidizing agents to oxidize melanin molecule and form yellow pale hair. Similar as process of perming, it opens the cuticle by alkaline solution and bleaching chemicals penetrate to the cortex, then melanin is oxidized and removed.
We cannot get a very light color without bleaching. Our hair bonds with chains of melanin. Our hair contains 2 types of melanin: eumelanin and phaeomelanin. Asian?s hair which is black and dark in color contains more eumelanin than phaeomelanin. Fair, reddish and blond hair has more phaeomelanin than eumelanin. Eumelanin is easier to be removed than phaeomelanin. Due to this reason, color of hair is lightened step by step; dark to red, orange, to yellow.
After bleaching our hair, coloring can start to fill in and bond to the porous cuticle. The effect of color chemical substance will fade easily. Some people like the bleached hair color. However, they still need to dye for color. If solely bleaching, the cuticle will be full of pores and brittle, luster and weak, and our hair looks very unhealthy. It may cause hair lossing or breakage.
