So I currently have two characters over 310 light on my account.
The first, my main, is just over 320 light. And for a long while now, I haven't had any green engram drop. Probably since I hit level 40. The lowest engram that will drop is a blue. Update: Since Rise of Iron, all of my accounts now drop greens.
However, on my second character, I still get green drops from a fair number of enemies. It's really annoying because greens end up being ~190 light max, and that is nowhere near what I want. But if it were blue I would at least have a shot of getting something good (either legendary, or high light).
I haven't done as many quests with this character, but I should be most of the way through the game at this point. I'm level 40, and, as I said, over 310 light. So why am I still getting green engrams as drops? Is there a particular point or trigger that causes me to stop getting greens?