The tab and the All Folders view rotation widget thing and the header pane in the message pane are gray. The folder pane and the quickfind toolbar are blue. The menubar and the toolbar and the tab strip are aero glass. There doesn't appear to be any rhyme or reason for why some toolbars are blue, some are gray and some are transparent. This visually clutters the interface without adding a lot of value. The large aero glass area is especially egregious because it allows the desktop to bleed through and clutter about 85% of the primary "toolbar" (control containing areas at the top of the app). I don't have a lot more to offer here except to say that it needs a serious clean-up.

This should be now more consistently. Closing it as WORKSFORME. If you think this needs more work, please reopen the bug.