Google Redesigned is a Mozilla Firefox extension designed by Globex Designs that aims to fully redesign the look and feel of popular Google services. This is achieved with Cascading StyleSheet (CSS) files which are loaded on the client's browser. The extension simplifies the use of these styles by providing auto-updates, easy management and notifications of changes. You can also download and use the styles individually by going to their respective pages.
Here's what Gmail looks like wearing the Redesigned skin:
You can freely download from the website http://www.globexdesigns.com/gr/