Just a few minutes ago,I was just checking my mails and Something happened to My Gmail windows and I saw the color was changed to Sky Blue.I Refreshed the page and got a message on the top which was pointing that Gmail have themes now.
Once the new option is enabled in your account (as usually, Gmail’s new features are slowly rolled out), you’ll find a tab named “Themes” in the settings page and you’ll be able to choose from 30 themes.
There are already 30 different themes to choose from — ranging from nature themes to shiny and chrome-style themes. Google has given Gmail a little makeover with crisper and cleaner lines (it reminds me of Google reader).
There are 30 themes available from which you can choose your favt. I am adding screenshot here. I am happy with gmail already but It would be a nice touch to have feature to personalize my gmail account.