Effect of Light Level on Color Prefernece and Specificaiton of Light Source Color Rendition

Substantial efforts have been made to investigate how light source color rendition affects color preference. It has been widely agreed that a source with a high color fidelity score may not result in higher color preference, as a higher saturation is generally preferred. Two psychophysical experiments were designed to investigate the color preference of an artwork under nine nearly metameric stimuli with a gamut area (i.e., IES Rg) between 99 and 124 across a wide range of illuminance levels (i.e., from 20 to 15000 lx) , which was never carefully studied before. These different Rg values of the stimuli were designed to be produced by systematic changes in IES TM-30 red and green chroma shifts. The findings revealed that the light level had a significant impact on color appearance and color preference, with a stimulus having a larger gamut area being preferred under a lower illuminance level. It suggested that light level should be considered when specifying light source color rendition .