Help with hair dye from Sally's?

Hi, I was wondering if you could help me with a "hair dilemma". My hair used to have golden blonde highlights in it. Yesterday, I used a tipping cap to "reverse" tip it. I pulled strands through and then coated them with a neutral medium brown haircolor from L'oreal Feria. Before I dyed it I put on a tinted warm brown protein filler from Sally Beauty so that the brown dye would take over the blonde highlights. I like this color, but I would like my hair to just be one, all over rich brown shade. Nothing too ashy and nothing too warm ( I do have a lot of red in my hair color).I'm not sure how this will go considering I still have some highlights poking through. I've heard great things about professional hair dye from Sally B's, but I have no clue where to start, what brand to buy, what developer, and how much to mix. I just want my hair color to look really rich (slightly warm, not brassy, but just a bit warm). I was wondering if anyone could offer any suggestions, and if I should use any sort of protein filler before I dye my hair. I really love how rich Kandee Johnson's (youtube guru) hair color is (not the color itself, just the evenness). Also, would demi-permanent dye cover my highlights? Or should I go straight for permanent? My hair is in pretty healthy condition.