I was having the same hang up so i searched and found this site, then figured it out how to fix it accidentally, so it thought i would share the solution :)
Pick the "Characters" theme in the personalization options, then close it. When you open it back up and click Windows Color you'll have a similar options menu to Vista, so you can pick the color and transparency of the theme. I like darker color themes so i was glad to find out how to fix this. (p.s. it may have something to do with me recently re-installing the drivers for my video card.... but probably not, so if you can re-install the drivers from your pc manufacturer or aftermarket video card M.F., then restart, then try this it should work.((as long as your video card isn't a pos, i.e. integrated ;) )) otherwise it