It struck me the other day whilst watching L8wrtr's fan edit of AOTC, which I believe he's colour graded to a degree.....my god. Once you change the colours (or do whatever it is he did) it really exposes the green screen. All the characters looked like they weren't actually there. I really couldn't believe how much it made them stand out from the background. Whilst the films have always been like a cartoon, the illusion that they're in these environments has mostly come across.

This may ultimately make it easier for ady to roto them out and then make new backgrounds that actually match the elements being superimposed.

Edit: It is of course possible that he didn't do any colour grading and I'm just noticing how bad it is for the first time.