This report is the fourth in a series from a large scale study that examines the effects of three office color interiors (white, predominately red, and predominately blue-green) on worker productivity. Matched. on relevant variables, participants were assigned to one of three offices and performed simulated office tasks for four consecutive days. Productivity was measured through workers' task performance and task accuracy, taking into account individual differences in environmental sensitivity (i.e., stimulus screening). The findings suggested that the influences of interior colors on worker productivity were dependent upon individuals' stimulus screening ability and time of exposure to interior colors. Implications of office workers' long-term productivity are discussed in relation to issues concerning the visual complexity of interior environments. (C) 2007 Wiley Periodicals, Inc.