What is the valid range for L*, a*, and b*?

L* ranges from 0 (pure black) to 100 (pure white). a* and b* are theoretically unbounded but in practice range from about −128 to +127 for colors within the sRGB gamut. Values outside these ranges are accepted and the resulting RGB is clamped to 0–255.

What happens when a LAB color is outside the sRGB gamut?

Many LAB colors—especially highly saturated ones—cannot be represented in sRGB. This tool clamps each R, G, B channel to the 0–255 range, which produces the nearest displayable color. The swatch will still be shown but it will not exactly match the original LAB value.

Which illuminant does this tool use?

D65 (standard daylight, 6500 K) with reference white Xn=0.95047, Yn=1.00000, Zn=1.08883. D65 is the default illuminant for sRGB and is the most common choice for web and display work.

What does L*=50, a*=0, b*=0 convert to?

L*=50, a*=0, b*=0 is a neutral mid-gray with approximately rgb(119, 119, 119) / #777777.

Is this the same conversion used in CSS Color Level 4?

Yes. CSS Color Level 4 defines the lab() function using the same CIE LAB D65 reference and the same LAB→XYZ→linear RGB→sRGB pipeline used here.

Does this tool send any data to a server?

No. All conversion math runs entirely in your browser using JavaScript. No data is transmitted anywhere.

LAB to RGB Converter

Name: LAB to RGB Converter
Availability: InStock
Author: Nham Vu

Enter CIE LAB (L*, a*, b*) values and instantly get the equivalent sRGB (0–255) color with a live preview swatch.

CIE LAB Input

L* (Lightness) 53.39

a* (green → red) 80.11

b* (blue → yellow) 67.20

#D50032

RGB Output

R (Red)

G (Green)

B (Blue)

Conversion Steps

1 LAB → XYZ (D65): X=0.3082, Y=0.1693, Z=0.0459
2 XYZ → Linear RGB: Rl=0.6500, Gl=−0.0891, Bl=0.0372
3 Linear RGB → sRGB (gamma): R=0.834, G=0.000, B=0.196
4 Scale & clamp to 0–255: R=213, G=0, B=50

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Summary

Enter CIE LAB (L*, a*, b*) values and instantly get the equivalent sRGB (0–255) color with a live preview swatch.

How it works

Enter L* (0–100), a* (−128 to +127), and b* (−128 to +127) using the number inputs or sliders.
L*, a*, b* are converted to XYZ tristimulus values using the inverse CIE f() function and D65 reference white (Xn=0.95047, Yn=1.00000, Zn=1.08883).
XYZ is multiplied by the inverse sRGB matrix to produce linear RGB channel values.
Linear RGB is gamma-encoded with the sRGB transfer function (IEC 61966-2-1) to produce non-linear sRGB in the 0–1 range.
Values are scaled to 0–255 and clamped, then the HEX code is derived from the clamped integers.
A live color swatch previews the resulting color; out-of-gamut inputs are clamped to the nearest displayable color.

Use cases

Translate perceptual LAB color specifications into screen-displayable RGB values.
Convert ICC profile LAB measurements into usable web color codes.
Verify that a LAB color is within the sRGB gamut before using it on a web page.
Generate HEX codes from CIE LAB brand color definitions.
Bridge color science workflows (spectrophotometry, ΔE calculations) with CSS/HTML color values.
Quickly estimate the RGB appearance of a LAB color from a color chart or research paper.
Cross-reference CIE LAB paint or ink specifications with digital sRGB equivalents.
Build color palettes starting from perceptually uniform LAB steps.

Frequently Asked Questions

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Last updated: 2026-05-28 · Reviewed by Nham Vu