LAB vs RGB vs CMYK vs HSL: which color space for which job
Designers use four color spaces, each solving a different problem. Using the wrong one loses color accuracy, fails a Pantone match at the mill, or breaks print production. This guide explains when to use each and why it matters, with no math PhD required.
Why there are four of them
Every color space is an abstraction that solves one specific physical or perceptual problem. RGB describes light emitted by pixels. CMYK describes ink absorbed by paper. LAB describes what the human eye actually perceives. HSL describes how humans intuitively categorise color.
A textile designer can easily use all four in a single day. Pick a color on screen in HEX. Send it to a US printer in CMYK. Specify the fabric dye in LAB. Document the brand system in HSL. Using the wrong one (say, specifying a fabric dye in HEX) causes real production failures. A color that looks deep navy on your monitor might dye out as muddy teal on cotton because HEX can't predict dye outcomes. LAB can.
The rest of this guide breaks down each space, when to use it, and the pitfalls to avoid.
The four color spaces
HEX / RGB
Digital screensThe color your monitor actually emits. HEX (#FF6B3D) is just RGB written in base 16. Every browser and design tool speaks this natively.
- Web and app UI
- Anything displayed on a screen
- Passing color from Figma to code
- Universal: every tool supports it
- Device-accurate for the specific display
- Not perceptually uniform
- Cannot match to physical ink or dye
CMYK
Print, ink on paperThe color space of ink. Cyan, Magenta, Yellow, Key (black). Every commercial print shop converts your file to CMYK before printing.
- Business cards, flyers, magazines, packaging
- Anything going on a commercial offset press
- Rich-black and spot-color specification
- Matches what the press actually does
- Printer-predictable
- Smaller gamut than RGB, so some colors impossible to print
- Needs ICC profile for exact match
LAB
Color matching, Pantone and other colour standards, textile dyePerceptually uniform: equal numeric distance = equal perceptual difference. Pantone and other physical colour standards publish LAB values for their swatches. Textile dye houses work in LAB.
- Working to a Pantone or other physical colour standard
- Textile fabric dye reference
- Color-critical brand specifications
- Computing CIEDE2000 Delta-E
- The only space where color-difference math is meaningful
- Device-independent: same L*a*b across monitors
- Counter-intuitive for visual picking
- a and b axes are negative-through-positive
HSL / HSV
Design systems, CSS tokensHuman-readable: hue, saturation, lightness. Lets you tweak one dimension at a time without shifting others.
- CSS variables for a design system
- Generating light/dark variants of a brand color
- Visual color picking in UIs
- Most intuitive for humans
- Easy to generate tints and shades
- Not perceptually uniform either
- Lightness varies by hue: yellow L=50 looks brighter than blue L=50
Quick decision table
Why textile specifically cares about LAB
Fabric dye is not pixel light. When a mill dyes a bolt of cotton, they're mixing chemical dyes to hit a specific absorption / reflection signature. That signature is measured with a spectrophotometer and expressed in LAB values. Pantone's textile system (TCX, Textile Cotton Extended) and other physical colour standards publish LAB values for every swatch because LAB is what the dye house can actually match to.
If you send a dye house a HEX code, they'll convert it to LAB internally, but their conversion assumes sRGB and D65 daylight. If your screen isn't calibrated to those, your intended color drifts. Sending LAB directly removes the ambiguity.
The CIEDE2000 Delta-E metric (the industry standard for "how close is this match") is calculated in LAB. A Delta-E under 2 is considered an acceptable match for commercial dye. Under 1 is near-perfect. No other color space makes this math meaningful.
For any textile project with color-critical branding, always deliver LAB values alongside HEX. Our Color Converter produces CIE-standard LAB (D65, 2° observer), the same basis Pantone and other colour standards use for their published values.
Related resources
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