Toggle between dark mode on and dark mode off. Select the moon icon to change the message window background to black. Now available in Office 365/Office 2019, a pop-up notes that: “In Black Theme you can now read your messages with a dark background… When reading a message, you can turn dark mode on or off by using the icon at the top of the message window. ; Next, from the menu, select Tools and then click on Add-ons. Go ahead launch your Thunderbird application on your Mac or PC and then press the Alt button on your keyboard to have the top-menu appear (as shown below). The feature is with the edge://flags settings page and has several different options to get the best look for different websites. That is Outlook, Windows 10 Mail, Zoho, and potentially Gmail. Dark Mode provides a Black Background instead of white for the Message Window . Once we apply Dark Mode in Microsoft Outlook , the same applies to all the other Microsoft Office Programs such as Word , Excel , PowerPoint and etc. Technically, the Windows 10 Mail App had a Dark Mode option prior to this update, but the switch only applied to its side menus. Normally, switching to dark mode in Windows will not influence the Office theme, and our test also prove this: However, according to your information, since your Outlook email background turns to white after changing Windows mode, we suggest resetting all your mode settings, including Office theme and Windows dark mode and see whether it works. Select the sun icon to change the message window background to white. In the search box at the top, type dark mode and you should see an option labelled 'Force dark mode for web contents'. How to Enable Dark Theme In Mozilla Thunderbird: 5 Steps . The dark text on dark background issue will happen with email clients that do support dark mode but don't support prefers-color-scheme. Once Dark Mode is selected, Outlook has changed into a Black Color Theme which includes Dark Mode. Re: Dark theme email background in Outlook A bit too late, but there are UI XML files in the ProgramData folders for each app that controls some of the base colors. I was looking into to replacing the default Blue highlights that appear when you highlight menu items - the … First Dark Mode in the reading pane hit the Outlook Web app and Outlook UWP app, and today we are happy to report that the feature has also come to the desktop Outlook app. Microsoft Edge allows you to force webpages into dark mode. So, to make the logo in email fully bulletproof, I’ll combine methods 1 and 4 from above.