PostCSS Color Functional Notation

npm install postcss-color-functional-notation --save-dev

PostCSS Color Functional Notation lets you use space and slash separated color notation in CSS, following the CSS Color specification.

:root {
	--firebrick: rgb(178 34 34);
	--firebrick-a50: rgb(70% 13.5% 13.5% / 50%);
	--firebrick-hsl: hsla(0 68% 42%);
	--firebrick-hsl-a50: hsl(0 68% 42% / 50%);
}

/* becomes */

:root {
	--firebrick: rgb(178, 34, 34);
	--firebrick-a50: rgba(179, 34, 34, 0.5);
	--firebrick-hsl: hsl(0, 68%, 42%);
	--firebrick-hsl-a50: hsla(0, 68%, 42%, 0.5);
}

Usage

Add PostCSS Color Functional Notation to your project:

npm install postcss postcss-color-functional-notation --save-dev

Use it as a PostCSS plugin:

const postcss = require('postcss');
const postcssColorFunctionalNotation = require('postcss-color-functional-notation');

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

Options

preserve

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

postcssColorFunctionalNotation({ preserve: true })

:root {
	--firebrick: rgb(178 34 34);
	--firebrick-a50: rgb(70% 13.5% 13.5% / 50%);
	--firebrick-hsl: hsla(0 68% 42%);
	--firebrick-hsl-a50: hsl(0 68% 42% / 50%);
}

/* becomes */

:root {
	--firebrick: rgb(178, 34, 34);
	--firebrick-a50: rgba(179, 34, 34, 0.5);
	--firebrick-hsl: hsl(0, 68%, 42%);
	--firebrick-hsl: hsla(0 68% 42%);
	--firebrick-hsl-a50: hsla(0, 68%, 42%, 0.5);
}

@supports (color: rgb(0 0 0 / 0)) {
:root {
	--firebrick: rgb(178 34 34);
	--firebrick-a50: rgb(70% 13.5% 13.5% / 50%);
}
}

@supports (color: hsl(0 0% 0% / 0)) {
:root {
	--firebrick-hsl-a50: hsl(0 68% 42% / 50%);
}
}

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.

postcssColorFunctionalNotation({ enableProgressiveCustomProperties: false })

:root {
	--firebrick: rgb(178 34 34);
	--firebrick-a50: rgb(70% 13.5% 13.5% / 50%);
	--firebrick-hsl: hsla(0 68% 42%);
	--firebrick-hsl-a50: hsl(0 68% 42% / 50%);
}

/* becomes */

:root {
	--firebrick: rgb(178, 34, 34);
	--firebrick: rgb(178 34 34);
	--firebrick-a50: rgba(179, 34, 34, 0.5);
	--firebrick-a50: rgb(70% 13.5% 13.5% / 50%);
	--firebrick-hsl: hsl(0, 68%, 42%);
	--firebrick-hsl: hsla(0 68% 42%);
	--firebrick-hsl-a50: hsla(0, 68%, 42%, 0.5);
	--firebrick-hsl-a50: hsl(0 68% 42% / 50%);
}

Custom properties do not fallback to the previous declaration