just from a description.
i don't know how to post pics so my interpretation is that this was
not a native bird. However it was about the size of a large budgerigar
mostly light green enough to seem yellow all over, and had the loudest call i have ever heard. Not much to go on but it was beautiful.
there was at least three of them, more yellow than green no markings at all that i could see, the nearest i can get to it is a ring necked parakeet, it looked like a man size canary, but with a slightly bulbous head.
so likely a type of parakeet, well i never, i saw them on the branches of the tree outside the flat, but their call was louder than some of those featured.
The other day I was watching one of them performing acrobatics on my miniature crab apple tree in a quest to get to the bird feeder. They use their beaks to help themselves climb along until they reach the peanuts. No other birds have touched the peanuts but the parakeets seem to make light work of them.