Delta E Color Difference Calculator

About this generator

Delta E is a number that answers the question "how different do these two colors look to a human eye?" Everybody who works with print, textiles, paint, or any kind of color-matched QA eventually learns it, and most people on the web side never do, which is unfortunate because it is also exactly the right tool for comparing two brand colors, two alleged duplicates in a design-system audit, or the output of a color pipeline before and after a transformation. This calculator takes two colors — HEX or RGB — converts both to CIE L*a*b* through the standard sRGB → linear sRGB → XYZ (D65) → Lab chain, and computes two different Delta E values. The first, ΔE76, is the original 1976 formula: a plain Euclidean distance in Lab space. It is intuitive, fast, and quite wrong near the blue end of the spectrum, where perceived color changes do not actually scale linearly with Lab distance. The second, ΔE2000 or CIEDE2000, is the Sharma-Wu-Dalal 2005 reformulation that most of the modern industry uses. It bakes in corrections for lightness, chroma, and hue — including a specific blue-region correction term — and it is the formula your professional color-matching software is almost certainly running under the hood. Both numbers are shown so you can see how different the "simple" answer is from the "correct" answer, which is itself part of the lesson. The verdict line translates the number into language that non-color-scientists can act on. ΔE below 1 is below the just-noticeable-difference threshold under good lighting — a human eye will not reliably see a change. ΔE between 1 and 2 is right at the JND; a trained eye in a side-by-side will catch it, a casual viewer will not. ΔE between 2 and 10 is visible at a glance even to untrained observers, which is where most brand-mismatch complaints live. Above 10 the colors are starting to live in different conceptual categories. For print QA, most reputable shops accept ΔE2000 ≤ 2 as a run match, and strict brand programs enforce ≤ 1.5 or even ≤ 1 for logo work. For digital work the thresholds are looser because monitor calibration variance dominates: a ΔE2000 under 3 across a design system is usually fine, under 5 is defensible, over 10 is a sign that two tokens are being treated as duplicates when they are not. The classic use case for the calculator is color-pipeline validation: run an image through a conversion (ICC profile, color-space transform, PDF export, screenshot codec round-trip) and measure the ΔE between the before and after of a few sample patches to decide whether the pipeline is lossless-enough for the job. It is also the right tool when a designer swears two colors in a palette are the same and a developer swears they are different — compute the ΔE and the conversation is over in thirty seconds.

Use Cases

• •QA a print run against a Pantone master by sampling swatches and verifying ΔE2000 ≤ 2.
• •Validate a color pipeline — ICC conversion, codec round-trip, canvas rasterisation — stays below the JND threshold.
• •Settle an argument about whether two near-identical hex codes in a design system are real duplicates.
• •Compare a Figma source color against its coded CSS value to catch rounding errors before they ship.
• •Benchmark one brand color against competitor brand colors to prove visual distinctiveness in a trademark filing.
• •Teach designers why their "slightly bluer navy" is or is not actually perceptible to users.

FAQ