Elofyn · Games · Color Code Trainer
3 modes · ΔE 2000 scoringColor Code Trainer.
A swatch appears. You type the color code. Delta E 2000 scores how close your eye is. Train HEX, RGB, and HSL — ten colors per round, daily seeded challenge.
// daily challenge
Same 10 colors for everyone today. Compare scores with a shareable result string.
// scoring
- ΔE < 1sub-JND90+
- ΔE 1–5close61–90
- ΔE 5–15visible22–61
- ΔE > 15off< 22
// choose mode
HEX
6-char hex code
#E07B3A
RGB
Three 0–255 channels
rgb(224, 123, 58)
HSL
Hue, saturation, lightness
hsl(22, 71%, 55%)
Your input never leaves your browser.
What is this?
Color Code Trainer is a browser-based game that trains your eye to read and write color codes. Each round shows you a color swatch — your job is to reproduce it as a HEX value (#rrggbb), an RGB triplet (0–255 per channel), or an HSL definition (hue 0–360°, saturation %, lightness %).
The game measures accuracy using Delta E 2000, the CIE perceptual distance formula that models how the human eye actually distinguishes colors. It rewards near-matches — a score of 90 + means your guess falls below the just-noticeable-difference (JND) threshold, meaning most people couldn’t tell the two colors apart.
Designers use it to build intuition for their color systems. Developers use it to sanity-check hex values without a picker. Students studying CSS, design systems, or photography use it to train color vocabulary. Ten colors per round, three format modes, a daily seeded challenge so you can compare scores with peers — no account required, nothing leaves your browser.