can anyone help please?

I have decided to quit highlighting, and be a brown-with-grey hair, but I have some brassy highlights from the last time I went to a salon. Before that I had a down-to-the ears virgin growth, and I wish I had come here for advice first. I got some Goldwell SilverBlonde, SilverBeige, and Silver Brown** semipermanent haircolor to play with. I would like to blend with the grey hair, and not try to cover it; I am tired of roots, and tired of fighting nature, and of trips to the salon and leaving with too much warmth in my hair.

 Anyway I wondered if I can use this semiperm stuff and some low volume peroxide, and maybe neutalize some of the brass, and blend the roots a bit without pulling a lot of red (hence the lower peroxide). Also will neutal filler help even up how the hair takes the color? I have shoulder-length hair, below the ears is highlighted, then back-tinted brown, then lightly highlighted again but not to as high a level. Above the ear is virgin hair that had permanent brown on it (the backtint), then highlights that came out brassy. Then, an inch of my root browwn with unevenly growing grey.

    Yes, I know that's a lot of different stuff going on, but I don't feel

that I can trust anybody else (no offense to hair pros here!).

 Heck if it's gonna get screwed up, I'd rather do it myself!

   ANY help, advice, input will be appreciated. Thank you!

**( levels 6,7, and 8--I've been told I'm a 5,51/2)