Any single green thing has a fairly good chance of being noticed – and perhaps sampled – by a nearby avian.
Chances improve if that green thing is lurking in a pile of assorted other non-green things.
If the green thing turns out to be tasty, it may be singled out for further scrutiny.
Take veggie chips, for instance.
(The setup: sometimes Mommy enjoys a late afternoon snack of veggie chips (potato = yellow, tomato = red, spinach = green).)