I can't really help with the Gmail issue since you didn't describe the problem. For example, can you view your Inbox when you go to https://mail.google.com/mail/u/0/#inbox in Firefox? Can you send mail? If the problem is that Gmail isn't your default mail program in Firefox when you click on a mailto link or use the "Email link" option from the Firefox toolbar, if enabled, see [[Change the program used to open email links]]. For the new color styles, see [[Personalize Firefox with Colorways]]. You can choose another theme, or you can restore your original theme by disabling the current one in Firefox Settings -> Add-ons and themes -> Themes. (Click the menu button [[Image:Fx89menuButton]], click ''Add-ons and themes'' and select '''Themes''' on the left.) See [[Use themes to change the look of Firefox]] for more information.