Hello, A theme is an add-on that changes the visual appearance of Firefox. You can switch to another theme as follows: #Click the menu button [[Image:Fx89menuButton]] and choose ''Add-ons and themes''. #Switch to the ''Themes'' panel. #*The built-in default System, Light, Dark and Alpenglow themes will be listed, as well as any themes you installed yourself. #Find the theme you want to use and click the ''Enable'' button. To uninstall any themes you installed yourself, click the ellipsis [[Image:Fx107-Addons-3dotIcon]] (3-dot) icon and click the ''Remove'' button. For more information about Firefox themes, see the articles [[Use themes to change the look of Firefox]] and [[Built-in themes in Firefox - alternative to complete themes]]. Did this answer your question? Let us know.