Color memory game's broken scoring formula called normal human guesses a failure

A developer built a browser game where players recreate brand colors from memory using hue, saturation, and lightness sliders, scoring each guess by measuring the color distance in CIE Lab space. The original scoring formula mapped a ΔE of 0–50 onto 100–0 points, but this meant the entire rating vocabulary compressed into a range far tighter than where real player guesses actually landed. After registering score as a custom metric in GA4 and collecting 232 samples, the developer found every round averaged below the lowest rating threshold, with 27.8% of guesses scoring a flat zero. The root problem was that a typical human guess sits around ΔE 37 — a competent performance — yet the old curve already treated anything past ΔE 27.5 as a failure. The fix raised the zero-point to ΔE 90 and added a gentle exponent curve, dropping zero-score guesses from 27.8% to 2.3% and aligning the rating bands with how people actually play.