UPDATE 3/9/13: i would not recommend this product for bleached hair. i recently had blond highlights put in my brunette hair, and they turned orange after about a week. i went back to my stylist in dismay, and the first question she asked me was "are you using argan oil?" i had been, every day. she was able to strip out the buildup with a special shampoo that returned my blond to the original platinum.
so be careful! it's wonderful, but best on natural dark hair.