Google has added themes into Gmail, to customize your inbox, go to the Themes tab under Settings, and you'll be able to choose from 30 themes. If you don't see them yet, check back soon, as usually, Gmail's new features are slowly rolled out. "We wanted to go beyond simple color customization, so out of the 30 odd themes we're launching today, there's a shiny theme with chrome styling, another one that turns your inbox into a retro notepad, nature themes that change scenery over time, weather driven themes that can rain on your mailbox, and fun characters to keep you in good company," informs Gmail's blog.
Gmail's help center provides an interesting tidbit about the new themes: "In some cases, you can also customize by location. Some themes change during the day, and we use the location information you provide to correctly time these changes with your local sunrise, sunset, and/or weather. If you select one of these themes, you'll see a Country/Region drop-down menu appear."
Gmail also adjusted the default theme, but you can always go back to the previous theme by selecting "Classic" in the settings page. I can't decide between Contrast Black, Cherry Blossom, Graffiti and Ninja. What's your favorite theme?