Bleached hair and new color..PLEASE HELP!

I have had the single process color OVER my bleached highlights and it DID turn out all one color. Actually, I had my color person add a few platinum highlights to it because I wanted that white look. I can't answer your question of "how" they do it because I didn't pay attention and I really don't know. I ended up going back to just having the heavy hightlights myself because that way you can get away with a little bit of root regrowth and not have to worry about running to the salon as often or say something comes up and you can't make it -- no problem. Whereas with the all-one-color you pretty much HAVE to keep it meticulously maintained. I don't recall it being cheaper for me -- I think it was actually more expensive. 

Realize you can/could have called your stylist to ask her these questions. And I would suggest you tell her your concerns/ask questions tomorrow when you get there just to make sure you two are on the same page. There are probably all different kinds of ways of doing color and who knows if she'll do it the way my girl did. One more thing -- I ended up with a band of discoloration at my root area when I got my all-one-color. It wasn't horrible, but I told the girl I didn't like what was happening, and she did something different, and I still had the problem. I don't know why. I ended up going somewhere else, and now I'm back to my regular heavy highlighting. When I first went to the person I see now I discussed going all one color versus the highlights and she thought the highlights were more economical for me and would give me the look I was trying to achieve, and I agreed.