PostCSS Lab Function

PostCSS Lab Function lets you use lab and lch color functions in CSS, following the CSS Color specification.

.color-lab {
	color: lab(40% 56.6 39);
}

.color-lch {
	color: lch(40% 68.735435 34.568626);
}

/* becomes */

.color {
	color: rgb(179, 35, 35);
	color: color(display-p3 0.64331 0.19245 0.16771);
}

.color-lch {
	color: rgb(179, 35, 35);
	color: color(display-p3 0.64331 0.19245 0.16771);
}

Usage

Add PostCSS Lab Function to your project:

npm install postcss postcss-lab-function --save-dev

Use it as a PostCSS plugin:

const postcss = require('postcss');
const postcssLabFunction = require('postcss-lab-function');

postcss([
  postcssLabFunction(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);

PostCSS Lab Function runs in all Node environments, with special instructions for:

Options

preserve

The preserve option determines whether the original functional color notation is preserved. By default, it is not preserved.

postcssLabFunction({ preserve: true })

.color {
	color: lab(40% 56.6 39);
}

/* becomes */

.color {
	color: rgb(179, 35, 35);
	color: color(display-p3 0.64331 0.19245 0.16771);
	color: lab(40% 56.6 39);
}

enableProgressiveCustomProperties

The enableProgressiveCustomProperties option determines whether the original notation is wrapped with @supports when used in Custom Properties. By default, it is enabled.

> [!NOTE] > We only recommend disabling this when you set preserve to false or if you bring your own fix for Custom Properties.
> See what the plugin does in its README.

postcssLabFunction({ enableProgressiveCustomProperties: false })

:root {
	--firebrick: lab(40% 56.6 39);
}

/* becomes */

:root {
	--firebrick: rgb(178, 34, 34); /* will never be used, not even in older browser */
	--firebrick: color(display-p3 0.64331 0.19245 0.16771); /* will never be used, not even in older browser */
	--firebrick: lab(40% 56.6 39);
}

subFeatures

displayP3

The subFeatures.displayP3 option determines if color(display-p3 ...) is used as a fallback.
By default, it is enabled.

display-p3 can display wider gamut colors than rgb on some devices.

postcssOKLabFunction({
	subFeatures: {
		displayP3: false
	}
})

.color {
	color: lab(40% 56.6 39);
}

/* becomes */

.color {
	color: rgb(179, 35, 35);
	color: lab(40% 56.6 39);
}

Copyright : color conversions

This software or document includes material copied from or derived from https://github.com/w3c/csswg-drafts/tree/main/css-color-4. Copyright © 2022 W3C® (MIT, ERCIM, Keio, Beihang).