The "green screen" appears at the top of the quiz edit page for some players. These are generally players who have a history of plagiarism, grammatical or spelling mistakes, non-cooperation with editors -- basically, people whose quizzes need a lot more work on the part of the editors. It's basically a block of text, with a green background, explaining that there's been a history of problematic quizzes; you'd know it if you saw it!
Many people who have had the dreaded "green screen" at one point or another have managed to shed it, through hard work -- if you turn your quizwriting around and start cooperating, submitting quizzes that need little correction, etc, it will update to reflect that.
A green screen means that there's a delay in when the quiz enters the queue that editors see. The author might submit the quiz on Tuesday, but an editor might not be able to see it until Wednesday when it makes it into the queue. (Those dates are only examples -- sometimes waits are longer.)
A quiz that has already been looked at does go to the bottom of the queue, but it's often looked at faster than completely new quizzes anyway. I know that when I first start the day's editing in a given category, I scan the list to see if there's a quiz I've already worked with, and I usually take care of that quiz first. Normally we like for one editor to take a quiz from start to finish, so I'm the best one to edit a quiz I've already seen, whereas any of the other editors will feel free to take on a quiz that hasn't been seen before. A quiz where I've seen and cleared most of the material before is also faster for me to look at than one I've never seen. It's just a matter of where and how to prioritize.
A player with a history of good submissions does find their quizzes going to the top of the queue. For example, a Thursday submission by IWriteGreatQuizzes will appear in the queue above a Wednesday submission by IDoNotProofreadMySubmissions.
Editor (Religion, Music, Humanities)
Just because there's twilight doesn't mean we can't tell the difference between night and day