brown weed is old weed. fresh cannabis, like most other vegetation is green. if you are smoking brown weed it is due to being old weed. cannabis has a shelf life. i haved seen weed from n cali that started out green(like always), and then the people had soooo much of it that they ended up sitting on it a while. the older it got the more it lost what chlorophyl it had remaining in harvested crop. Cannabis, just like anyother harvested plant will start to rot once it ias picked. Refrigeration slows this process down.

dai*ma