3 doman plums from colibri pink and I've got ice blue. Fed it 1 pineapple (with message), so hopefully I've got white next time.
Personally, I've witnessed the fact that no matter how many fruits you feed it, if it doesn't get the "growing new feathers" message, the color won't change at all. So that's at least necessary for a color change. Now my question is whether that's simply bad luck/good luck RNG, or whether you're not "hitting on" a new color on their dye scale when you don't get the message.