Alongside this plugin I've written a tutorial on creating Gatsby.js plugins.

This is a sub-plugin for gatsby-transformer-remark. As demoed below, add this plugin to the options of gatsby-transformer-remark.

Install

npm install --save gatsby-remark-color-highlight

How to use

// In your gatsby-config.js
module.exports = {
  plugins: [
    {
      resolve: `gatsby-transformer-remark`,
      options: {
        plugins: [`gatsby-remark-color-highlight`],
      },
    },
  ],
};

Note: If you are using gatsby-remark-vscode and want to highlight color hexcodes in your code examples, make sure that it’s listed before this plugin.

Options

• wrapperElement: The tag that you want to wrap your color hexcodes with. Defaults to "code"
• className: The class you want to add to your wrapping element. This can not be set to an empty value. Defaults to "color-highlight"
• searchNodeTypes: The AST node types that you want to search for color hexcodes. Will search all child nodes deeply. Defaults to ["text", "paragraph", "inlineCode", "html"]