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 September 27, 2020 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, a dark user interface, and more. Older versions of Opera supported themes, but the browser no longer supports dedicated theme files. Opera supports two types of customizations: wallpapers and general-appearance tweaks. These procedures work on all currently supported versions of Opera for Windows and Mac, although they might vary slightly between the two. This process was tested using Opera version 71 in macOS. Enabling Wallpapers Wallpaper appears in the back of certain default browser tabs. To enable and customize this feature: Click the gear icon at the bottom of the left-side menu to open Preferences (macOS) or Settings (Windows). Alternative, use the Alt+P keyboard shortcut on Windows or the Cmd+, shortcut on macOS. Slide over the Enable wallpapers toggle to allow for a background image. Pick from the list, select Add your wallpaper to upload an image, or choose Get more wallpapers to visit Opera's add-ons site. Appearance Tweaks Opera allows a few other ways to customize its appearance, too: Toggle the sliders to Enable dark theme or Show bookmarks bar.Use the drop-down menu to change the font size of the application.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.Adjust the page zoom using the drop-down menu.Tell Opera to highlight links and form fields when you press Tab. Sidebar Customization The sidebar that runs along the left edge of the browser includes a handful of stock elements. Use the sliders to show or hide the sidebar and elements, and to show or hide notification badges for each of those elements. In Settings, select Manage Sidebar. Choose the items you'd like to see in the sidebar.