Pantone to LAB Converter

Search any Pantone spot colour and get its CIELAB coordinates — L*, a* and b* under the D65 illuminant. CIELAB is the device-independent reference colour science and quality control are built on.

Values are computed from each Pantone colour's published sRGB equivalent, converted through XYZ under D65.

Or jump to a common Pantone colour
Pantone
Pantone 186-C
#C8102E

CIELAB (D65 / 2° observer)

L*
42.54
black → white
a*
65.89
green → red
b*
35.71
blue → yellow
The same colour in other models

What is CIELAB (L*a*b*)?

CIELAB, usually written L*a*b*, is a mathematical description of colour published by the Commission Internationale de l’Éclairage in 1976. Unlike RGB or CMYK it is not tied to any device: it describes what a colour looks like to a standard human observer rather than what a particular monitor or press does to produce it. That independence is why it sits underneath almost every colour-management system in use today.

It has three axes. L* is lightness, running from 0 at pure black to 100 at diffuse white. a* runs from negative green to positive red. b* runs from negative blue to positive yellow. The two chromatic axes are deliberately built as opponent pairs, mirroring the way the human visual system encodes colour after the retina — you can perceive a yellowish red, but never a reddish green, and CIELAB is structured to reflect that.

The design goal was perceptual uniformity: a fixed numeric distance should look like a similar amount of colour change anywhere in the space. CIELAB only partly achieves this, which is precisely why the colour-difference formulas evolved. Simple Euclidean distance is ΔE*ab, or CIE76. CIE94 and then CIEDE2000 added corrections for the regions where CIELAB’s uniformity breaks down, particularly in blues and in near-neutral colours. ΔE*00 is the metric this site ranks all its industrial-system matches by.

Two details always travel with a Lab value, and it is meaningless without them: the illuminant and the observer. D65 approximates average daylight at roughly 6500 K and is the standard for graphic arts and screen work; D50 is used in some print environments. The 2° standard observer models a narrow field of view, and the 10° observer a wider one. The values on this page use D65 with the 2° observer, which is the combination Pantone, RAL and NCS all publish against.

Pantone vs CIELAB: how they differ

Side-by-side comparison of the Pantone Matching System and CIELAB
Pantone (PMS)CIELAB
Type of systemA catalogue of physical ink formulasA mathematical colour space — no physical samples
Device dependenceTied to specific inks and paper stocksDevice-independent by design
What the value meansAn index number pointing at a recipeCoordinates describing appearance to a standard observer
Range1,341 discrete coated coloursContinuous — every value in between is valid
InterpolationNot possible between catalogue numbersNative — the space is continuous and measurable
Used forSpecifying and reproducing brand colours in printQuality control, ΔE tolerance, colour management, research
RequiresA fan deck and controlled viewing conditionsAn illuminant and observer to be stated — D65 / 2° here
Measured byVisual comparison against a printed guideSpectrophotometer

Worked Pantone → LAB conversions

Pantone 186-CL* 42.54 a* 65.89 b* 35.71#C8102E
Pantone 286-CL* 26.46 a* 31.69 b* -62.21#0033A0
Pantone 355-CL* 54.14 a* -54.00 b* 38.86#009639
Pantone 116-CL* 84.45 a* 3.17 b* 85.39#FFCD00
Pantone COOL-GRAY-9-CL* 50.27 a* -0.51 b* -2.04#75787B
Pantone BLACK-6-CL* 7.84 a* -0.97 b* -6.75#101820

Each Pantone colour above is shown with the CIELAB (D65 / 2° observer) values this tool computes for it. Unlike a cross-standard match, this conversion is a calculation rather than a nearest neighbour — there is no ΔE, because nothing is being approximated.

Who converts Pantone to LAB?

Lab values are what you reach for when a colour has to be measured rather than described.

  • Print quality controlPress operators measure printed sheets with a spectrophotometer and compare the Lab reading against the target. The ΔE between them decides whether the sheet passes.
  • Supplier colour tolerancesA contract that says “match Pantone 186 C” is ambiguous. One that says “ΔE*00 ≤ 2.0 against L* 45.6, a* 67.2, b* 32.1 under D65” is enforceable.
  • Cross-material brand consistencyPrint, textile, plastic and coating suppliers all use different colourants. Lab gives them one shared target that does not assume any particular process.
  • Colour management and ICC profilesICC profiles use Lab as their profile connection space, so every conversion between two device profiles passes through it.
  • Textile and plastics developmentDye houses and compounders work in Lab and ΔE because visual matching across batches is unreliable at production scale.
  • Colour research and academic workPerception studies, colour-difference research and standards development all express results in Lab coordinates.

How to use this Pantone to LAB converter

This conversion is a calculation, not a match — there is no approximation and no ΔE, because nothing is being substituted.

  1. Enter a Pantone number or name in the search box and select the colour from the suggestions.
  2. Read the computed L*, a* and b* values, calculated under the D65 illuminant with the 2° standard observer.
  3. Copy the full Lab string for a specification, or read the individual axis values from the breakdown grid.
  4. State the illuminant and observer whenever you pass a Lab value to a supplier — a bare triple is ambiguous and cannot be verified.
  5. For contractual work, measure the physical Pantone chip with a spectrophotometer rather than relying on values derived from an sRGB equivalent.

Accuracy — read before you specify a colour

The Lab values here are computed from each Pantone colour's published sRGB equivalent, converted through CIE XYZ under D65 with the 2° standard observer. The arithmetic is exact and reversible. What it cannot do is substitute for measuring the physical chip: Pantone's own spectral data for a spot ink differs from the sRGB approximation used to display it on a screen, because sRGB cannot represent every colour a spot ink can produce. For quality control, specification tolerances or anything contractual, measure the actual printed sample with a spectrophotometer.

Lab is the space colour differences are calculated in. ΔE*ab (CIE76) is simple Euclidean distance between two Lab points; CIEDE2000 (ΔE*00) corrects for the regions where CIELAB is not perceptually uniform and is the modern default — it is what this site uses to rank every industrial-system match. As a guide, ΔE*00 below 1 is imperceptible, 1–2 is a commercial match, and above 5 the colours read as clearly different.

In short: conversion values on this page are approximate, because the two systems use different colourants and cover different gamuts. Verify against the official physical colour standard before committing to production, tooling or a signed-off brand spec.

Frequently Asked Questions

L* is lightness on a 0–100 scale, where 0 is pure black and 100 is diffuse white. a* is the green-to-red axis, negative toward green and positive toward red. b* is the blue-to-yellow axis, negative toward blue and positive toward yellow. The two chromatic axes are opponent pairs, which mirrors how human vision encodes colour after the retina.
Because colour appearance depends on the light falling on it. The same ink measured under daylight and under tungsten produces different Lab coordinates. Stating the illuminant — D65 for daylight, D50 in some print workflows — makes the value reproducible. The observer matters too: the 2° standard observer models a narrow field of view and the 10° a wider one. Values on this page use D65 with the 2° observer.
It answers a different question. RGB describes what a display emits, CMYK what a press lays down, and both change meaning between devices. CIELAB describes appearance independently of any device, which is what makes it the right space for measurement, tolerance and colour management — and the wrong one for telling a monitor or a press what to do.
ΔE is the distance between two colours in Lab space. The original ΔE*ab (CIE76) is straight Euclidean distance. CIEDE2000 (ΔE*00) adds corrections for the areas where Lab is not perceptually uniform, especially blues and near-neutrals, and is the modern standard. Rule of thumb: under 1 is imperceptible, 1–2 is a commercial match, 2–5 is visible side by side, above 5 reads as a different colour.
Yes, though the two directions are not symmetrical. Pantone to Lab is a calculation with one right answer. Lab to Pantone is a search for the nearest colour in a finite catalogue, so it returns a closest match with a ΔE attached. The LAB to Pantone converter on this site does exactly that, ranking the whole coated deck by CIEDE2000.
Close, but not identical, and the difference matters for measurement work. Pantone measures its physical inks spectrally; the values here are computed from the sRGB equivalent used to display each colour on screen. Since sRGB cannot represent every colour a spot ink produces, saturated colours in particular will differ. Use these figures for design and comparison work, and measured spectral data for quality control.