Measure perceptual color difference between two sRGB colors using CIE76, CIE94, and CIEDE2000 — the same formulas designers, paint mixers, and print houses use to judge whether two colors are visually distinguishable.
| Component | Color A | Color B | Δ |
|---|---|---|---|
| L* (lightness) | — | — | — |
| a* (green↔red) | — | — | — |
| b* (blue↔yellow) | — | — | — |
| C* (chroma) | — | — | — |
| H° (hue angle) | — | — | — |
ΔE < 1.0 — Not perceptible by the human eye.
1 – 2 — Perceptible through close observation.
2 – 10 — Perceptible at a glance; common in print proofing tolerance.
11 – 49 — Colors are more similar than opposite.
100 — Maximum (opposite colors, e.g. black ↔ white).
CIE76 is a straight Euclidean distance — fast but the eye is not equally sensitive in all directions of Lab space, so it overstates differences in saturated regions.
CIE94 introduces chroma and hue weighting tuned for graphic arts.
CIEDE2000 further corrects for blue rotation, neutral-color flattening, and lightness — and is the de facto modern standard. All three are computed from L*a*b* derived from sRGB via D65 white point.