Color vision deficiency screening test resistant to display calibration errors

A method for testing a plurality of regions in a color space to identify any of, or a subcombination of, the following color vision deficiencies: protanopia, deuteranopia, tritanopia, and related anomalies. A set of distractor colors is distributed across a region of color space such that the confusion line through a single target color intersects approximately the middle of the set. The distractor set spans a region extending in both chromaticity and luminance, which provides leeway for display errors since the confusion line will intersect the set even if colors do not render exactly as specified, and color deficient observers would still not be able to identify the target. A web-based implementation enables remote testing of subjects.