Fig. 1

Color-matching real-world objects and skin under low-pressure sodium light, which impairs retinal mechanisms for color vision. a Participants (N = 20) used a computer to match the color of real-world objects (items listed in panel b) and skin (four female actors, 2 Caucasian, 2 African American), first illuminated by low-pressure sodium light and then broad-band white light (inset shows illuminant spectra). Each  participant was seated so that they could view the test stimuli shown to them by the experimenter, as well as a 2 × 2 cm viewing window in an otherwise light-tight box through which they could see a color-calibrated monitor (21.5-in. iMac computer, pixel resolution 1920 × 1080). Participants used a mouse to navigate a color-space disc and lightness strip, setting the hue, brightness, and chroma of the test patch to make the color match. Photographs and spectral measurements of objects are given in Supplementary Fig. 1. b Color-appearance matches made by all participants for the 35 test stimuli. The swatches are rendered using the RGB values as matched on a calibrated monitor (white point: XYZ = 87.4, 100, 57.7). Participant information: average age 27.5 (range 19–33); 10 female; 12 Caucasian; four Asian (italics); three African American (bold); one South-East Asian (italic bold). Source data are provided as a Source Data file