I personally don't have any experience with dark mode.

According to Google, visitors can set dark mode in their browser, and when they access websites that offer dark mode, the website will be displayed in dark mode, while all other visitors will see the website in light mode.

In WebSite X5, you can specify the colors for fonts, background, etc. in dark mode using CSS code.

----- WebSite X5 -----

    1 Settings > Statistics and Code / Code

        Custom Code:
        Before the closing HEAD tag

            @media (prefers-color-scheme: dark) {
               body {
                       background-color: black;
                       color: white;
                       }
             }

-------------------------

This is just a small example, otherwise wait for the experts, maybe they already have more comprehensive solutions for WebSite X5 that also take forms and much more into account.

I prefer light websites, but if visitors want to view my websites in dark mode, they can do so without making any changes to my web pages.

----- My website without dark mode -----

----- My website with dark mode (Firefox extension "Dark Reader") -----

The Dark Reader browser extension is available for free for Chrome, Safari, Edge, and Firefox; donations are welcome.

The Dark Reader browser extension allows visitors to use dark mode, regardless of whether the website operator has enabled dark mode.

>> https://darkreader.org/