In college, we had brown or black for trash, blue for recycling.
In another college, we had green or blue for trash, green or blue or white for recycling; the difference is the label on the trash/recycling dumpster.
In another city, recycling used to be green with a label, and any container was fine for trash when the city didn't provide trash cans. Now they provide the trash/recycling cans; green is for yard clippings, blue is for trash, and gray is for recycling.
In another college, we had green or blue for trash, green or blue or white for recycling; the difference is the label on the trash/recycling dumpster.
In another city, recycling used to be green with a label, and any container was fine for trash when the city didn't provide trash cans. Now they provide the trash/recycling cans; green is for yard clippings, blue is for trash, and gray is for recycling.
...and...recycling as explained in Monty Python's "Meaning of Life":
HUMPHREY: All right, settle down. Settle down. [clunk] Now, before I begin the lesson, will those of you who are playing in the match this afternoon move your clothes down onto the lower peg immediately after lunch, before you write your letter home, if you're not getting your hair cut, unless you've got a younger brother who is going out this weekend as the guest of another boy, in which case, collect his note before lunch, put it in your letter after you've had your hair cut, and make sure he moves your clothes down onto the lower peg for you. Now,--
WYMER: Sir?
HUMPHREY: Yes, Wymer?
WYMER: My younger brother's going out with Dibble this weekend, sir, but I'm not having my hair cut today, sir.
PUPILS: [chuckling]
WYMER: So, do I move my clothes down, or--
HUMPHREY: I do wish you'd listen, Wymer. It's perfectly simple. If you're not getting your hair cut, you don't have to move your brother's clothes down to the lower peg. You simply collect his note before lunch, after you've done your scripture prep, when you've written your letter home, before rest, move your own clothes onto the lower peg, greet the visitors, and report to Mr. Viney that you've had your chit signed.