They are blue at the computers at school too. The computers at school have XP, we have vista at home, I think it may have something to do wit that also. Just a guess
No, it has absolutely nothing to do with your operating system. You're using IE6, that's why.
BTW - the blue "new" bars are now a dark red for everybody. That issue is resolved regardless of browser.
Again, and I reiterate, first hit F5. Everyone reading this, just do it. Seriously - the problems people are seeing are because of a clash between cached files and the new ones. Hitting F5 "blows out" the old stuff, thus fixing most problems (except the blue headers). Then, if you're using IE6, upgrade to IE7 or Firefox. The blue headers will go away.