Hair bleaching is a chemical hair dye technique that strips the color of your hair strands. Bleaching begins with an alkaline agent that opens up the hair cuticle. Next comes the oxidative agent that penetrates the hair cortex and dissolves the hairs natural melanin (your hair’s natural color). The longer you leave this agent in your hair, the lighter in color your hair becomes. You hair can either lighten to a yellow or reddish tone depending on the your natural hair tone and then eventually lighten to platinum blonde.