Scoop 2 ounces of hair lightener into a color bowl -- the measuring spoon usually comes in the container -- one scoop equals 1 ounce. Add 2 ounces of 40-volume color developer. Rinse out the scoop and dry it before you put it back into the lightener container if you use it to measure the developer, too. Blend both ingredients together with a color brush until the mixture is an even consistency.
Divide your hair into four equal parts using the handle of the color brush. Dab lightener onto the dark roots of hair along the parts to wet the hair and keep it sectioned. Apply the lightener, one section at a time, to the dark portions of hair only. Part each section off into small, 1/2-inch subsections and apply the color to the top and underside of roots in each subsection.
Wait 45 minutes, or until the color of your roots closely matches the blonde color on the ends of your hair.
Rinse thoroughly to remove the lightener. Shampoo hair a couple of times to make sure you got it all washed away. Squeeze the water out of your hair.
Pour 1 ounce of toner and 1 ounce of 5-volume color developer into a color bottle. Close the lid and shake to mix. Pour the toner mixture over your wet hair, working it in with your fingers. Wait 10 minutes, then rinse, shampoo and condition.
Retouch those nasty black roots every four weeks to keep your platinum tresses looking gorgeous. Nothing detracts from stunning blonde quite like dark regrowth.
If you have scrapes, cuts or scabs on your scalp, let your scalp heal before tackling your root job.