Im not sure I have real dark brown hair but I didnt try it. I really think it would take more than one box though. With only using one box it will probably only take some color out of your hair and leave with with yellow/orange/red tint. Thats what happened when I tried using a lighter color to get a dirty brown.
Hm... well, I was hoping to dye my bangs purple but I wanted to lighten them first. Do you think they'd turn out right if this stuff tints them like you said? Obviously this would be my first experience with coloring my hair, haha XD
Im not positive but I think maybe if you just do your bangs and are able to use more of the box it will lighten better than if you were to try to do your whole head .. I hope that helps :)
It will as long as you have bleached your hair and maybe leave on for the max amount it says u can leave it then dry your hair and put on the purple or whatever other color you want, the lighter color will pull in the pigments lol