Internet, Networking, & Security Browsers Change Themes in the Opera Web Browser Modify wallpaper, fonts, and Opera's user-interface elements by Scott Orgera Writer Scott Orgera is a former writer who covering tech since 2007. He has 25+ years experience as a programmer and QA leader, and holds several Microsoft certifications. our editorial process Facebook Twitter Scott Orgera Updated on January 15, 2020 sandsun / Getty Images Browsers Chrome Safari Firefox Microsoft Tweet Share Email Adding and changing the appearance of Opera is a breeze. Modern versions of Opera include support for wallpapers, font configuration, and a dark user interface. Older versions of Opera supported themes, but the browser no longer supports dedicated theme files. These procedures work on all currently supported versions of Opera for Windows and Mac, regardless of the operating-system version. This process was tested using Opera version 65. Open the Settings or Preferences Menu Select the Opera menu button, located in the upper left-hand corner of your browser window. When the drop-down menu appears, select the Settings option (Windows) or the Preferences option (macOS). Alternative, use the Alt+P keyboard shortcut on Windows or the Cmd+, shortcut on macOS. Customize Your Browser Opera supports two types of customizations: wallpapers and general-appearance tweaks. Wallpapers In the Wallpapers section of the Settings window, slide the Enable wallpapers button to allow for a background image. This wallpaper appears in the back of certain default browser tabs. Pick from the list, or select either Add your wallpaper to upload an image or Get more wallpapers to visit Opera's add-ons site. Appearance Tweaks Toggle the sliders to activate a dark theme or reveal the bookmarks bar. Use the drop-down menu to change the font size of the application, or select Customize fonts to change the fonts your browser uses. You'll be able to pick a standard system font as well as specific options for a serif, sans-serif, and fixed-width font, as websites specify. Customize the Sidebar The sidebar—which runs along the left edge of the browser—includes a handful of stock elements. Use the sliders to show or hide the sidebar and to show or hide notification badges for each of those elements. Add a check to the box to show an icon for that element in the sidebar. Remove checks to suppress the item.