Measure perceptual color difference using the ΔECIEDE2000 metric. Color Distance Calculator is a free online tool from the ToolsRift Color Tools collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Enter two colors and the tool reports the CIEDE2000 ΔE distance along with a plain-English read on how similar they are.
A number describing how different two colors look to the human eye. Lower means more similar; 0 means identical.
A ΔE of about 1 is the threshold of a just-noticeable difference; values under 1 are usually indistinguishable.
CIEDE2000 models human perception far better than raw RGB distance, especially for blues and near-neutral colors.