# PostCSS Gamut Mapping [<img src="https://postcss.github.io/postcss/logo.svg" alt="PostCSS Logo" width="90" height="90" align="right">][PostCSS]

[<img alt="npm version" src="https://img.shields.io/npm/v/@csstools/postcss-gamut-mapping.svg" height="20">][npm-url] [<img alt="CSS Standard Status" src="https://cssdb.org/images/badges/gamut-mapping.svg" height="20">][css-url] [<img alt="Build Status" src="https://github.com/csstools/postcss-plugins/workflows/test/badge.svg" height="20">][cli-url] [<img alt="Discord" src="https://shields.io/badge/Discord-5865F2?logo=discord&logoColor=white">][discord]

```bash
npm install @csstools/postcss-gamut-mapping --save-dev
```

[PostCSS Gamut Mapping] lets you use wide gamut colors with gamut mapping for specific displays following the [CSS Color 4 Specification].

When out of gamut colors are naively clipped the result can be radically different.  
A saturated and bright color will be much darker after clipping.

To correctly adjust colors for a narrow gamut display, the colors must be mapped.  
This is done by lowering the `chroma` in `oklch` until the color is in gamut.  

Using the `@media (color-gamut)` media feature makes it possible to only use the wide gamut colors on displays that support them.

```pcss
p {
	background-color: oklch(80% 0.05 0.39 / 0.5);
	color: oklch(20% 0.234 0.39 / 0.5);
	border-color: color(display-p3 0 1 0);
}

/* becomes */

p {
	background-color: oklch(80% 0.05 0.39 / 0.5);
	color: rgba(50, 0, 20, 0.5);
	border-color: rgb(0, 249, 66);
}

@media (color-gamut: rec2020) {
p {
	color: oklch(20% 0.234 0.39 / 0.5);
}
}

@media (color-gamut: p3) {
p {
	border-color: color(display-p3 0 1 0);
}
}
```

## Usage

Add [PostCSS Gamut Mapping] to your project:

```bash
npm install postcss @csstools/postcss-gamut-mapping --save-dev
```

Use it as a [PostCSS] plugin:

```js
const postcss = require('postcss');
const postcssGamutMapping = require('@csstools/postcss-gamut-mapping');

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

[PostCSS Gamut Mapping] runs in all Node environments, with special
instructions for:

- [Node](INSTALL.md#node)
- [PostCSS CLI](INSTALL.md#postcss-cli)
- [PostCSS Load Config](INSTALL.md#postcss-load-config)
- [Webpack](INSTALL.md#webpack)
- [Next.js](INSTALL.md#nextjs)
- [Gulp](INSTALL.md#gulp)
- [Grunt](INSTALL.md#grunt)

[cli-url]: https://github.com/csstools/postcss-plugins/actions/workflows/test.yml?query=workflow/test
[css-url]: https://cssdb.org/#gamut-mapping
[discord]: https://discord.gg/bUadyRwkJS
[npm-url]: https://www.npmjs.com/package/@csstools/postcss-gamut-mapping

[PostCSS]: https://github.com/postcss/postcss
[PostCSS Gamut Mapping]: https://github.com/csstools/postcss-plugins/tree/main/plugins/postcss-gamut-mapping
[CSS Color 4 Specification]: https://www.w3.org/TR/css-color-4/#gamut-mapping