This is a study that concludes that birds that are more colorful are more aware of their vulnerability to predators than the dull colored ones. And, although this was done on passerines that molt into nuptial plumage in order to compare their reactions to when they were in basic (aka non-breeding) plumage, I think it can be extrapolated to parrots.
https://www.sciencedaily.com/releases/2 ... 095820.htm