Whoa whoa whoa.....
Are we really sure that's what caused it? I thought the title was a joke. If that is the case and we can see proof, that's fine, but I am skeptical. I feed all my birds Zupreem ( natural, not colored ) and I've never had any problems. ( On a side note, when I was new to birds I fed colored zupreem without any ill effects. ) This includes the Eclectus, and that includes random blood panels to monitor health.
In the past, I've seen a bird like that online & in one of my books. I recall it saying that the bird was actually a hermaphrodite, which is why the coloring was unique.
If it's from deficiency, then it's sad, but if it's not....I think that looks rather cool.