Gary Robert Allen

Color Preference under LEDs with Diminished Yellow Emission

Abstract A psychophysical experiment was conducted to investigate brightness perception and color preference under illumination from typical 3000 K blue-pumped light emitting diode (LED) A19 lamps (BP-LED) and 3000 K blue-pumped LED A19 lamps with diminished yellow emission (YD-LED). Eighty-seven participants between 19 and 25 years completed brightness matching and preference comparisons between two full-size side-by-side rooms that contained chromatic objects and still life arrangements, with one lamp type in each room. Participants had higher overall preference to the room illuminated by YD-LED. Specifically, red, green, orange, and wood objects were preferred under YD-LED; no preference was found for neutral, yellow, and blue objects between the two lamp types. The words saturated, vivid, vibrant, pleasant, inviting, colorful, stand-out, distinct, appealing, and comfortable were reported as reasons for the color preference under YD-LED; dull, dead, and fade were used by participants to describe the lower color preference under BP-LED. Skin tone preference under the illumination of these two lamp types was significantly different between Asian (n = 32) and Caucasian (n = 52) participants. Caucasians evaluated their own skin tone more favorably under YD-LED, with the average assessment that skin appeared healthy and colorful under YD-LED but grey and pale under BP-LED. No preference between the two lamps was found among Asians for their skin tone, though some Asians thought YD-LED rendered their skin too red and odd. Many existing measures of color preference and gamut were able to predict the higher overall preference to YD-LED, but they could not predict the preference of specific colors or for ethnic groups. The higher saturation and preference for red and green colors under YD-LED illumination is consistent with the higher red–green opponent signal provided by YD-LED. Coupled with several past studies, the spectral region around 570–580 nm appears to be deleterious to color and brightness perception.