EVALUATION OF PSYCHOLOGICAL IMPRESSIONS OF TWO-COLOR GRADATION LIGHTING

Advances in LED technology have opened possibilities for new lighting design utilizing colored light. In this study we carried out an experiment to evaluate the psychological impression of a space illuminated by two-color gradation lighting. We produced lighting equipment using LEDs that emitted two different colored lights separately in front and upper directions. The wall and ceiling of the experimental booth were illuminated by two colored lights changing continuously from the lower part of the wall to the ceiling. The results of this study indicted that psychological impressions of the two-color gradation lighting were composed of three factors; comfort, activity and temperature. The comfort was related to saturation and hue of colored light. The activity factor was strongly influenced by saturation of the colored lights. The warmth factor was closely related to hue of the colors.