Word for Windows launched in 1989. From there, through Word for Windows 2.0, Word 5, Word 6, Office 95, Office 97, Office 2000, and Office 2003 the system colors defined the look of the application. With Office 2007 that changed. Office 2010 gives you three whole schemes to choose from. Office 2013 still has only three schemes, but not the same three: they're worse.
Why? Why Bill? Why?