If you are referring to a toolbar icon, look for a disabled extensions in your addons "extensions" disabled extensions appear after enabled ones. If you are referring to the white print on black background buttons/menus within the search webpage, that is because Mozilla changed the default home page from a Google page to a one of their own. You can set your home page to be one from Google such as http://www.google.com or other page of your choice. The Google application choices to not show up automatically, you will want to make sure you are signed into Google, and that you have visited the Google application. see https://support.mozilla.com/kb/How%20to%20set%20the%20home%20page#w_restore-the-default-home-page