While marijuana is now legal in Colorado, you can still be fired for testing positive for the substance. The Washington Post reports that the state supreme court ruled 6 to nothing this week against a man who was trying to get his job back after failing a drug test. Colorado now becomes the fourth state to rule against an employee in such a case. The fired man argued that he wasn’t high at work, insisting that pot’s intoxicating chemical, THC, can stay in the system for weeks. The court offered no exception for marijuana used medically. The man had been a telephone operator at Dish Network for three years before failing the test.