This is how I go from black to blonde hair with my buzz cut. Mix 1 ounce of powder lighter with 2 ounces of your developer. Leave it on for the max amount which is usually 40 to 45 minutes to get your hair as light as possible on the first round. It really depends on what your scalp can handle if it is sensitive. The next day if you have gotten your hair light enough the first time, tone it with Wella T 14 for 20 or so minutes. Check the color every 5 to 10 minutes to be sure it is the shade that you like. Shampoo out the color, fully and condition your hair.