The emotion of disgust motivates a focus on physical purity. Physical purity, in turn, is commonly associated with the color white. Consequently, the disgust-inspired goal of preserving purity may engender a special focus on white and deviations from pure white. Across four studies, I tested the hypothesis that disgust-as a trait and/or state-is associated with hyper-sensitivity to subtle deviations in luminance at the extreme light end of the visual spectrum. Study 1 tested participants' ability to make subtle grayscale discriminations and whether this ability varied as a function of end of spectrum (light end vs. dark end), trait disgust, and trait fear. Additionally, emotional content was primed via exposure to disgust, fear, or neutral facial expressions. As predicted, trait disgust-but not trait fear-predicted enhanced ability to make subtle lightness discriminations but only for light-end trials. The emotional primes did not influence performance. Study 2 assessed participants' ability to detect a faint stimulus against a solid background (white or gray). Again, trait disgust-but not trait fear-predicted performance but only for the light-end trials (i.e., white background). In Study 3, state disgust, which was induced using emotional images, selectively enhanced the ability to detect deviations from pure white, but only for easily-disgusted individuals. In Study 4, I tested whether inducing a purity-focused mindset (by having participants view images of cleaning products) could have the same perception-enhancing effects as induced disgust. Differences across the experimental conditions at pre-manipulation baseline, which indicate a failure of random assignment, precluded the testing of this hypothesis. Nonetheless, the trait effect was once again observed: those who indicated that they were easily disgusted, were particularly good at detecting deviations from white. Altogether, the results support the conclusion that the emotion of disgust-both as state and trait-tunes perception so as to prioritize ranges of visual input that are central to the goal of preserving physical purity. Note: Abstract extracted from PDF text