Of course, if it is an emergency, I let them go, but otherwise they owe me 5 cents from their classroom money card if they choose to go when their stick has been changed to red. Sometimes I can really tell if it is a emergency or not by reminding them they will owe me 5 cents. It's amazing how quickly they change their mind:) At the end of the day one student changes all the sticks back to green for the next day!
Here is a picture of my chart in my room. We use the number system in my class, so that is why you don't see the names on the library pockets!
#6 has their stick changed to red