I have just had my hair done, only do it once a year at the salon and just do home hair dye kits the rest of the year. I LOVE the colour - she said it is a mix of 5.35 with some 4 added so it is a dark chocolate colour with hints of auburn. She suggested using 5.35 at home but looking online it does seem my hair has come out quite a bit darker than that, and is much closer to the pictures of a 4 and it has a hint of auburn as well. So I was wondering if it is possible to buy both a 4 and a 5.35 and then mix the colours together? I have dyed my hair for over 25 years but never actually done this - is it possible? I would assume you just squeeze both colour tubes into a bowl with both the developers and then just apply it?