A WordPress block to add a toggle between light and dark appearances, as seen on my blog. Adds a theme-dark class to the body element, when toggled on. The user's preference is then saved in local storage.

Read about it on my blog →

When toggled, the block will add a .theme-dark class to the body of the site. You can add CSS variables to target dark styles.

I did it this way on my blog, which uses the theme.json settings.custom.color values for each color, unless there is a color created within the Site Editor with corresponding slug (i.e. theme-1-dark). I used this method so that a user could manipulate any given color without having to modify theme.json.

/* Dark styles */
.theme-dark body {
    --wp--preset--color--theme-1: var(--wp--preset--color--custom-theme-1-dark, var(--wp--custom--color--theme-1-dark));
    --wp--preset--color--theme-2: var(--wp--preset--color--custom-theme-2-dark, var(--wp--custom--color--theme-2-dark));
    --wp--preset--color--theme-3: var(--wp--preset--color--custom-theme-3-dark, var(--wp--custom--color--theme-3-dark));
    --wp--preset--color--theme-4: var(--wp--preset--color--custom-theme-4-dark, var(--wp--custom--color--theme-4-dark));
    --wp--preset--color--theme-5: var(--wp--preset--color--custom-theme-5-dark, var(--wp--custom--color--theme-5-dark));
    --wp--preset--color--theme-6: var(--wp--preset--color--custom-theme-6-dark, var(--wp--custom--color--theme-6-dark));
}

1. Clone the repository into your WordPress plugins directory.
2. Run npm install to install dependencies.
3. Run npm start to start the development server.
4. Activate the plugin on your local WordPress site.
5. Add the block to a post or page.