14 DAY TRIAL // The Mountain View-based company may prepare a new Gmail feature requested by numerous users but there's no official confirmation on this. The rumor was launched by Philipp Lenssen of Google Blogoscoped who wrote that "a source is telling me that Gmail will get themes - custom layouts to personalize Google's web mail client. According to the source, the launch of this may happen within the next months. There will be 12 themes to pick from, according to this information, like a black-and-green 'terminal' view, as well as a flowery view."
Obviously, this would be a great addition for numerous users because the interface of a service or application is quite important for most of them. However, some Gmail users are not too surprised by such an update and point to other features which could bring better functionality to the Google mail service. For instance, lots of users requested the implementation of folders because they allow a better organization of the messages. Sure, Gmail has labels but for some, it's not enough.
At this time, Mozilla Firefox users have the ability to modify the Gmail interface by their own options using a special plug-in called Greasemonkey or modified stylesheets. At this time, there is a large number of Gmail skins available on the web, obviously for free, which could help you modify the interface of the mail service.
As Philipp Lenssen points out, Google is not a company focused on themes and visual style because, even if it owns a large number of products, only two of them could be customized with themes. One is the ex-Google Personalized Homepage (the actual iGoogle) which comes with support for themes offered for free by Google. Recently, Google has updated iGoogle with artist themes which let users personalize their own homepage with special visual styles such as Coldplay and Dolce & Gabbana.