You can alter the basic theme properties in Vista just like in XP, from the Appearances options in Control Panel - Display Properties, or just right click the Desktop, choose Properties, then get to it from there. If you really want a black background like that it's entirely possible.
I can't stand pure white myself as the main background for windows, etc, so I make them a slightly darker shade of grey with the RGB amounts of 235,235,235 which works out nicely - at least for me.
But pure black... ugh, I'd go insane with that. Try different combinations of color settings, perhaps you'll find something that's pleasing in terms of contrast that's better than white text on pure black and easier on your eyes as well.
As for the rest of the theme components, a lot of that is tied directly into the default color schemes of Vista, and would require some mods and edits of specific system files to allow for new themes to be put in place. There's a lot of 'em out there now, and it doesn't require "third party software" - just typically a patch to some Windows system files that then allows you to use themes designed by other people.