The 2013 RC version is now available here!
Blue theme update:  The Blue theme is now part of Visual Studio 2012 Update 2 (http://www.microsoft.com/en-us/download/details.aspx?id=38188), and is no longer included as part of the extension as of version 2.3.  Please ensure VS Update 2 is installed if you want to update the extension while continuing to use the Blue theme.
 
Allows users to customize the Visual Studio 2012 color palette.  This extension is supported for Visual Studio 2012 Professional and higher.  This Channel 9 video gives an in-depth description of how to use the extension.
Key features
Special thanks to Andrew Sarratori for helping with development!
Version history
2.3 
Added support for merging Fonts & Colors customizations with a theme, removed the Blue theme (now a part of Visual Studio 2012 Update 2)
2.2
  Move Themes menu into the Tools menu, improve visual appearance of the Color Themes launch page, add preview support when editing themes, added ability to import and export themes
2.1
  Fix broken theme list when several popular extensions (including ReSharper) are installed, and persist column sorting options
2.0  Initial release