Alright, I decided to give this calculator a go now that I'm starting on an alt's chocobo. Going for wine red, started feeding earlier on my own, and landed at pumpkin orange. Went to the calculator and put in the information, and got this:

Pumpkin Orange » Wine Red

RGB(193, 109, 31) » RGB(62, 17, 14)

Difference: Red: -131, Green: -92, Blue: -17

Feed the following to change to your desired colour:

11 × Apples, 15 × Pears, 22 × Berries

Note: If any of the above fruits in your recipe are quite high, it is recommended to alternate them with the others when feeding, so that you do not max out your RGB values by feeding all of the same type of fruit at once.
I broke it down like this when I fed:

5 berries, 3 pears, 2 apples, 4 berries, 3 apples, 4 pears, 5 berries, 1 apple, 1 berry, 4 pears, 3 berries, 1 apple, 4 pears, 4 berries, 4 apples

The "growing new feathers" message began on the fourth berry, and appeared for every fruit after. At the point where I broke my "rotation" and fed berries twice with only one color in between instead of two, it was just a mistake, but I don't think it should hurt anything. Will report back later with an update on what I got. By the way, here's the pumpkin orange chocobo, if anyone's curious about the color:



Screenshot was taken in late evening (when I happened to see it) and, of course, my chocobo blinked in the middle of it, so sorry for the quality!