Awhile back I read in a BTC magazine that If you want perfectly toned highlights .. Mix bleach and hair color. Can't remember what the exact ratio was, and I think they said a level 7. I know you don't have to use a level 7 but I've only been doing hair a few years and have never purposely mixed bleach with color. Does anyone do this? How does it turn out? Just kid of scared to try it on someone..