Purpose: to create an atmosphere of "uniformity", or, compliance, if you will. E.g. Scrubs: pink = nurses. navy blue = techs (nurses aides, etc), teal green (OMG, surgeons), purple (I, don't know...maybe housekeeping/custodians), let's see, then there is the cafeteria staff.......A monkey suit is a uinform that one wears to work every day. The military does it, sanitary engineers do it...I could go on. Benefit: Does save money on duds.