I'd like to try your product. I have a couple of questions. I'm naturally a coopery/light auburn going gray in that "yellowing" fade that red hair goes gray. I would guess it's at least 40 - 50%. Several months ago, did henna which I felt was too "bright" for me (not to mention the greuling application process.) My roots are coming in very light. I'd like to go "richer" in color without going too much darker. I was wondering if I could mix an auburn shade with a blonde to temper some of the red. I'm having trouble finding a shade that looks natural as I age. I also think that too dark would be more aging. Also my hair is just below shoukder length and very thick/coarse. I assume I need two bottles ? Thank You.