Today when I logged into my GMail Account, I got surprised. It was amazing that now mailbox was looking something different and then I realized that it was all because of New Gmail Themes Recently Introduced by Google . Now there is no more need to use any kind of extension to Make use of Themes in your GMail account, google has make this feature In-Built. To change your GMail theme log in to your GMail account and go to Settings and Select Themes Tab . Select any theme out there. And also tell us the Themes you liked. [via] Official GMail Blog