npm install postcss-color-hex-alpha --save-dev

PostCSS Color Hex Alpha lets you use 4 & 8 character hex color notation in CSS, following the CSS Color Module specification.

body {
	background: #9d9c;
}

/* becomes */

body {
	background: rgba(153,221,153,0.8);
}

Add PostCSS Color Hex Alpha to your project:

npm install postcss postcss-color-hex-alpha --save-dev

Use it as a PostCSS plugin:

const postcss = require('postcss');
const postcssColorHexAlpha = require('postcss-color-hex-alpha');

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

PostCSS Color Hex Alpha runs in all Node environments, with special instructions for:

• Node
• PostCSS CLI
• PostCSS Load Config
• Webpack
• Next.js
• Gulp
• Grunt

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

postcssColorHexAlpha({ preserve: true })

body {
	background: #9d9c;
}

/* becomes */

body {
	background: rgba(153,221,153,0.8);
	background: #9d9c;
}