Abstract
Color appearance data for eight dim (20 td) monochromatic test stimuli (480–620 nm, 20 nm steps) were obtained at four-min intervals following presentation of a photobleaching stimulus (9.62 deg, 5500K, 6.55 scot td, 10 sec). Both the test and photobleaching stimuli were centered at 10 deg temporal retinal eccentricity. The 2.55 deg test stimuli (500 msec duration) were selected to fill the perceptive fields of the four basic hues (blue, green, yellow, red). The time intervals were chosen to correspond to points before and along the cone and rod plateaus of the dark adaptation function. Data from four observers showed the largest change in hue ratios across time for the middle-wavelength stimuli. As expected, as rod contribution increased, observers reported the stimuli became more desaturated, though no decrease in saturation was observed for the shortest- and longest-wavelength stimuli. Results of this study will be discussed within the context of perceptive field sizes, foveal color appearance, and unique hues.