Wide gamut lighting and color contrast in anomalous trichromacy

LED lighting provides considerable flexibility for shaping the light spectrum for different applications, including increasing the color gamut. While the spectra are typically designed for their effects on observers with normal color vision, the chosen spectra could also enhance color perception in color-deficient observers (Tamura et al. 2015, 2017), and could potentially emulate the effects of filter aids for color deficiencies. We examined the consequences of typical or wide-gamut luminaires for color deficient observers. Protanomalous and deuteranomalous individuals have altered L- or M-cone spectral sensitivities that result in a compression of the color contrasts along the L vs. M axis of cone-opponent space. Light sources designed to increase these contrasts would thus be expected to amplify the L vs. M signals for color-deficient observers. We modeled the effects of different luminaires on color contrast for normal trichromats and protanomalous or deuteranomalous observers. For this we notionally illuminated the spectral reflectances of Munsell surfaces that were selected to yield a uniform circle of 36 hues in a cone-opponent space under an equal energy white luminaire for a color normal trichromatic observer. We then illuminated these surfaces with typical illuminants and the Rec.2020 UHDTV wide color gamut standard to evaluate chromatic contrast for color-anomalous observers and normal trichromats. The results illustrate the potential for modern wide-gamut light sources to enhance color contrast for anomalous trichromats.