Before making the switch to Chromium/Blink, Opera browser powered by Presto engine supported the themes, but Chromium based Opera 15, 16 and 17 versions doesn’t support themes. Opera 18 which is currently on Next stream supports themes and installing them in it is easy, here is how to do that.
Installing themes in Opera 18
1. Visit Themes page in Opera Add-ons gallery site
2. Double click on any theme you like and click on “Add to Opera” once its page opens, that theme will be installed.
See Speed Dial or Opera start page, if you like it keep it or install another theme and make it as default. FYI, you can see all installed themes and manage them by visiting “opera:themes” page.
To remove a theme, in Opera:themes page, hover mouse pointer over cross symbol at bottom of theme image and click. As Chrome offers theme creator Opera too offers Theme Creator extension.
Update: Read How to Create your Own Theme for New Opera?
Opera now offering instructions on how to make themes for their Chromium based browser. So why late? start making themes for your Opera browser.