Island to island variation comes into play. But it is important to understand that as a base, Caribbean Amazons are a blend of Northern South American Amazons that have been blown-in, on the backs of Hurricanes and the island hopping of the Native Humans as they transited the Caribbean and South America.
It would not be uncommon for there to be vast differences between younger coloration and Adult coloration with this family of Amazons! Just seeing a large group of island Amazons, even in captivity, is heartwarming as we are little more than ten years out from that set of back to back hurricanes that wiped several islands empty of any life!