In Los Angeles, racial demographics have changed radically in the past 30 years resulting in inevitable tensions in the school. This paper reports on a classroom simulation of ethnicity/race and class relations. Students adopted the roles of three polarized and rigid "color groupings": (1) Greens--ruling class, wealthy since birth; (2) Blues--working class, children and grandchildren of immigrants; and (3) Grays--extremely poor, lacking in education and marketable skills. Each student randomly selected a group, to mimic the "accident of birth," and memorized his or her group's behavior. Students then gave themselves a new name and attempted to find people of their own color group without asking another person to state his or her color. Participants quickly adopted their given roles while reflecting a splintered society. Emotions ran high and the project leader insisted that no one engage in physical contact during the simulation and that voices not be raised. Many students professed surprise at the intensity with which they felt their adopted position. Per student suggestions, adult supervision in such simulations should be kept to a minimum. Two appendices list each color group's behaviors and give detailed directions for simulation participants. (RJM)