I came on to look for ways to change the themes and all I've seen is indifference from Microsoft and frustration from users - big surprise - this grey theme is a usability nightmare, my eyes hurt after only using it for a while and it's SO UGLY.
I went from 2007 to 2013 but I wish I'd got 2010, I loathe this one and am going back to 2007. Might try out Open office, I hear that's pretty good.