How ColorGuesser Scoring Actually Works

People notice this pretty quickly: two guesses that look about the same distance from the target can score very differently. That’s not a bug.

ColorGuesser uses CIE94 to score guesses, not plain RGB distance. The difference matters because human vision isn’t uniform. We’re much more sensitive to shifts in some parts of the color spectrum than others. A small change in certain greens looks obvious. The same sized change in blue might be barely noticeable. RGB distance doesn’t know that.

CIE94 works in CIELAB, a color space built to match how we actually see. Equal steps in the space are meant to feel equal to the eye. It also weights lightness, saturation, and hue separately, because we don’t perceive changes in those the same way.

So if your guess is technically close but wrong in a direction the eye is sensitive to, it scores worse than a guess that’s further away in a direction we don’t notice as much. It’s a more honest measure of how wrong you were.

If you want to see the raw numbers for a puzzle, the color tools page has everything.