Peroxide can be used to lighten hair, either to make it appear more blond or in preparation for adding another colored dye. However, peroxide can be damaging to hair, and if used excessively may lead to dryness and brittle strands.
Peroxide needs to be exposed to the sun in order to change the color of hair. For the best results, hair should be liberally sprayed with a solution of no more than 3 percent peroxide before the hair is exposed to the sun for about an hour. Hair should be well-conditioned the next time it is washed to counteract the drying effects of the peroxide.