I had the same dilemma as you a few years ago as evidenced here:
http://forum.square-enix.com/ffxiv/t...oloring-system

On 2 occasions I got soot black, I changed either the amount of fruits needed or the order. The calculator is not as accurate as it’s lead to be believed. When you get stuck in a loop, change things up a bit and you’ll hopefully land on it. It worked for me that way. Good luck.