A composite light source includes a plurality of illumination panels, that emit light of a fixed color and a variable luminous intensity. Over time, the luminous intensities of at least two of the illumination panels vary, while a combined luminous intensity of the illumination panels remains about constant. Another composite light source includes a plurality of illumination panels that emit light. Each illumination panel of at least a first subset of the plurality of illumination panels emits the light with a first luminous intensity, and each illumination panel of at least a second subset of the plurality of illumination panels emits the light with a second luminous intensity that is different from the first luminous intensity.