Hi I currently have a lady who is a base 6/7 the hair is throwing out some red tones and she wants to go a natural blonde she is willing to use bleach with oplex but I was hoping on some advice with a toner as I know it will obviously need this. What is a good toner to use and how to use the toner for killing any brassy tones of may give please.she also knows this isn't going to be an over night one time thing and may take a few times befor reaching the goal.