Green Xanax bars are a powerful drug with both short-term and long-term effects .Xanax in types of different shapes and sizes and other varieties of colors, reason regarding different colors is the manufacturer of the drug wanted to make sure that their product is different. Xanax helps to calm the nervous system and induces feelings of relaxation. Xanax has the potential to be abused and can lead to dependence. If you are new and want to take Xanax, you may know how long it affects the body.