The effects of varied lighting and coloring in the classroom environment were examined on the behavior of seven severely handicapped 8 to 11 year olds with behavior problems. Analysis of changes in systolic blood pressure indicated that Ss were more comfortable and relaxed in the experimental room (in which the fluorescent lights were replaced by lights simulating sunshine in the visible and ultraviolet spectrum). Blind Ss were as affected as sighted Ss. Aggressive and nonattentive behaviors appeared more frequently in the afternoon than the morning, while destructive behavior was more likely to occur in the morning. (CL)