Okay so I'm wanting to dye my hair a medium/dark brown all over and I don't want to go to the salon for just one color. I've never done box dye before. The problem is, my hair right now is like a dirty blonde on top and a medium brown in bottom from when I dyed it at a salon over a year ago. If I get the brown color I want will my whole head turn out the same color? As in the brown and blonde turn the same color brown I want? Or do I need to bleach it or do something to my hair before I dye it the brown? I'm just confused. Thanks.