I decided to deviate from single fruit feeds as I seemed to be looping through Currant Purple, Marsh Green or Deepwood Green. So, I used the calculator from this thread to see if that would help get me to Soot Black.
Starting at Marsh Green (I had tried the feeding Berry only and ended up with Deepwood Green from that previously) I have fed 2 berries, 1 apple, 1 pear.
This shows as taking the RGB from 55, 63, 39 to 45, 53, 39 (goal being 47, 47, 39). Bit worried about the green value but it gives a colour estimate of Soot Black so crossing my fingers for the result in 1hr 20mins now.
Putting in 2 berries only did give an estimate of Soot Black but the value was 45, 53, 49 and I was concerned with the Blue showing as +10 over the approx. RGB value. I hope this works lol. At least with 2 colours in the range so close and only a little over with green it's got to be on the right track surely? >.>
Although.... now I'm wondering if I should feed another apple to get 50, 48, 34 arghhhhhh!!