The Office 2010 beta version has more features included when compared to the technical preview released back in July 2009. One of the changes is the availability of themes or color schemes similar to the ones in Office 2007. You can change the color scheme of Office 2010 and the Office suite contains three themes for your customizations- Blue, Silver and Black. Once you change a theme, this theme will be available in all the Office 2010 applications.
To change the theme, click on the file tab from any of the office application and select options in the File tab.
This will open up the options windows and select the General tab in the options and here you can see Color Scheme under User Interface Options.
Once you change the color scheme, all the Office 2010 applications will follow the same color scheme. You can change the color scheme from any Office 2010 application.