Hi, was hoping for some advice from some more experienced home hair-dyers 
I have very dark brown hair naturally with quite a bit of greys silver streaks coming through the roots.
I've bought a permanent dark brown to use but my hair has lots of slightly lighter tones, especially through the ends, which I like. I don't really want to end up with all one colour dark brown hair.
I was wondering if I used a medium brown instead would it be more likely to preserve the 'tonal' look ?(because I would be hoping the very dark brown bits wouldn't actually lighten to med brown).
Would be very grateful for any tips/advice.