A method of selecting a set of color sources for an image display system, the image display system creating a color image from at least three single-color color sources. According to one embodiment of the present invention, the method comprises selecting a first, second, and third color source. The first and second color sources are divided into a high-efficiency group and a low-efficiency group based on the efficiency of the color source. If the first color source is selected from the high-efficiency group (1102), the second color source may be selected from either the high-efficiency group or the low-efficiency group (1104). If the first color source is selected from the low efficiency group (1102), the second color source is selected from the high-efficiency group (1106). According to one embodiment of the present invention, the third color source is selected (1108) without first sorting the third color sources into high and low-efficiency groups.