Elucidating the effect of yellow illumination on color confusion in the semiconductor-related manufacturing industry

This study investigates how yellow lighting and white lighting affect color confusion in contrast with how sunlight does by using the Farnsworth-Munsell 100 Hue Test System (FM100). Forty college students with normal color vision are enrolled in this study. The experimental setup involves ceiling lighting at a 90° angle on the FM100 with an illuminance of 550 lx, in which the subjects view the FM100 at a 45° angle. All color chips of the FM100 that are fully discriminable under sunlight are arranged in a color circle (FM100 color circle) with equal hue steps resembling those of a 100 Munsell hue circle. Under colored lighting, however, colors may be undistinguishable, resulting in the misplacement of some of the color chips. Color confusion is then determined by counting the number of times a color chip is misplaced, which is called an error score. All error scores are plotted on the FM100 color circle, which is called the color error sheet, to reveal the range and severity of color confusion due to the colored lighting. Experimental results indicate that, although yellow lighting significantly introduces color confusion, white lighting does not. Additionally, yellow lighting does not cause serious impairment in distinguishing between the yellow (its own color) and blue colors (complementary of yellow), but causes significant impairment in distinguishing between the green and red colors. On the error scoring sheet, both the two nonconfusion series and the two confusion series are complementary and orthogonal. This observation allows us to postulate that, although colored lighting does not cause significant impairment in distinguishing between its own complementary colors, it does between its orthogonal colors.