From your start menu, all programs, stardock, objectdesktop, open WB not WB7, this will be WB 7 with old interface with the colours tab.
Hopefully there's an easier way in WB7 that I'm just not finding, or maybe they didn't get the option into the program yet?
System colours are not there yet but i don't think they will change much when added.
anyone else know any other easier softer ways?
Not easier, but it sounds like you use some walls smaller than your screen res so have them centered? You can make a image that matches your screen res the colour you want, then one by one paste walls into center of it and save them.