HueSense

Guides to Color Difference and Color Perception

Everything you need to read your test results properly: what ΔE numbers mean, how the human eye tells colors apart, why screens and lighting change your results, and the color tolerances used in real-world work.

  1. 01 What Is Delta E (ΔE)? — CIE76 vs CIE94 vs CIEDE2000ΔE expresses the difference between two colors as a single number. We compare the formulas and examples to show where the 1976 straight-line formula fell short and what CIE94 and CIEDE2000 fixed.
  2. 02 How Do We Tell Colors Apart? — Cone Cells and Opponent ProcessingFollow light as it stimulates the retina's three types of cone cells and the brain re-sorts those signals into red–green, blue–yellow and brightness channels, to understand how color discrimination works.
  3. 03 Why Discrimination Varies by Hue — MacAdam Ellipses and Uniform Color SpacesMacAdam ellipses are drawn large in the green region and small in the blue region. Learn why the size of a noticeable difference on the chromaticity diagram varies from color to color, and how color spaces evolved to correct it.
  4. 04 How Your Monitor, Brightness and Room Lighting Change Color Test ResultsHow the limits of 8-bit displays, color gamut and gamma, night mode, brightness, ambient lighting and viewing angle affect color discrimination test results, and how to keep conditions consistent.
  5. 05 Color Discrimination in Design and Print — Tolerances and Quality ChecksHow ΔE is used to set color tolerances in brand color management, print proofing and textile and paint color matching, plus the standard light sources, viewing conditions and tests used to compare colors in practice.
  6. 06 How to Improve Your Color Discrimination — What Practice Can and Can't ChangeHow far can practice improve color discrimination? A look at research on perceptual learning and color categories, how to make the most of Practice mode, and how to compare your results properly.
  7. ΔE ΔE Color Difference Examples by SizeSide-by-side tables of real sRGB color pairs built from red, yellow, green, blue, purple and gray base colors at ΔE00 differences from 0.5 to 10, with values from all three color difference formulas.