postcss-lab-function

What is postcss-lab-function?

The postcss-lab-function package is a PostCSS plugin that allows you to use the CSS Lab color function in your stylesheets. This function enables you to define colors in the CIE LAB color space, which is a more perceptually uniform color space compared to RGB or HSL. This can be particularly useful for creating color schemes that are more consistent and visually appealing.

What are postcss-lab-function's main functionalities?

Convert LAB colors to RGB

This feature allows you to write colors in the LAB color space in your CSS, and the postcss-lab-function plugin will convert them to RGB for you. This makes it easier to work with LAB colors without worrying about browser compatibility.

/* Input CSS */
body {
  color: lab(54.29% 80.82 69.88);
}

/* Output CSS */
body {
  color: rgb(255, 0, 0);
}

Support for alpha transparency

This feature allows you to include an alpha transparency value in your LAB color definitions. The plugin will convert these to the appropriate RGBA values in the output CSS.

/* Input CSS */
body {
  color: lab(54.29% 80.82 69.88 / 0.5);
}

/* Output CSS */
body {
  color: rgba(255, 0, 0, 0.5);
}

Custom properties support

This feature allows you to use CSS custom properties (variables) with LAB colors. The plugin will convert the LAB colors to RGB and preserve the custom properties in the output CSS.

/* Input CSS */
:root {
  --main-color: lab(54.29% 80.82 69.88);
}
body {
  color: var(--main-color);
}

/* Output CSS */
:root {
  --main-color: rgb(255, 0, 0);
}
body {
  color: var(--main-color);
}

Other packages similar to postcss-lab-function

postcss-color-function

The postcss-color-function package allows you to transform colors using functions like color-mod(). It supports various color manipulations such as lightening, darkening, and adjusting hue, saturation, and lightness. Unlike postcss-lab-function, it does not specifically focus on the LAB color space but provides a broader range of color manipulation functions.

postcss-preset-env

The postcss-preset-env package lets you use modern CSS features, including color functions like lab(), in your stylesheets. It automatically converts these modern features into a form that is compatible with older browsers. While it includes support for LAB colors, it also provides a wide range of other modern CSS features, making it a more comprehensive solution compared to postcss-lab-function.

postcss-color-mod-function

The postcss-color-mod-function package allows you to modify colors using the color-mod() function. It supports various color adjustments such as lightening, darkening, and blending colors. This package is similar to postcss-lab-function in that it provides advanced color manipulation capabilities, but it does not specifically focus on the LAB color space.

README

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:

Node	PostCSS CLI	Webpack	Gulp	Grunt

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).