How to Customize a WordPress Content Block for Dark Mode

In a previous article, we setup the WordPress Twenty Twenty Theme to support Dark Mode. You may have noticed that the solution was not perfect. For example, the “Become a Member” content block on the homepage become washed out and unreadable.

This is because the background color of that content block was set to white overriding the Theme’s color scheme. To fix this, we are going to use the Additional CSS Class(es) option for the content block to set both a light and dark background color instead. The values I enter will be based on the Twenty Twenty theme, however the basic process is the same regardless of theme.


How To Add Dark Mode Support to the WordPress Twenty Twenty Theme

Dark Mode is now here on most devices and supported in all modern browsers using the prefers-color-scheme media query. There are many benefits to Dark Mode support on our devices including accessibility, power saving, and personal preference. For example, when there are too many light or bright colors on the display the content becomes unreadable to those with certain vision impairments.

However, the next major hurdle in Dark Mode support are our websites and web applications. Despite the devices and apps providing a usable dark interface, most websites still do not. If you publish a blog, you can begin to better support your users by enabling a Dark Mode version of your website, blog, or application. Here’s a great article that goes into much more detail about Dark Mode and the prefers-color-scheme media query.

In this article, we will add Dark Mode support to a WordPress site using the Twenty Twenty theme.


Does Your Browser Support Dark Mode? It Should

2019 became the year of Dark Mode. Nearly all consumer Operating Systems (OS) received updates this year to support Dark Mode. Some devices, like Android phones, may have these updates delayed by their manufacturer, carrier, or both. I wrote last week on how to setup Dark Mode on these various devices.

My favorite part is that all Browser vendors have released this year (or will release shortly) Dark Mode capable browsers. This is not just changing the user interface to match the devices Dark Mode setting. This is also supporting the prefers-color-scheme CSS media query so that websites and web applications can adjust to Dark Mode as well.

Current Browser Support

The following browsers currently support the prefers-color-scheme CSS media query.

  • Chrome (76 or later)
  • Edge (76 or later)
  • Firefox (67 or later)
  • Opera (62 or later)
  • Safari (12.1 or later for MacOS and 13 or later for iOS/iPadOS)

The new Edge with support for the prefers-color-scheme media query is scheduled for release tomorrow. However, anyone can try it out today.

Internet Explorer and all older versions of these browsers do not support the prefers-color-scheme media query.

Does Your Browser Support Dark Mode?

Regretfully, at the time of writing, my blog does not yet support Dark Mode and the prefers-color-scheme media query. However, I created a CodePen to help you find out if your browser is ready. Check it out.

It is likely that your browser is ready. You may notice various sites already adjust to Dark Mode for you that previous had a Light Mode interface (e.g., If you create or maintain websites and web applications, now is a good time to start developing support for a Dark Mode interface in addition to a Light Mode. I will be writing more on how to do this starting next week.