I would like to use a different background fill for a vertically longer page (our contact page). Does anyoen know how to accomplish this within VSD? Thanks in advance.

You can set the background for each page different. With the page in front of you on the design screen click on "Page" at the top of VSD. Then in the page properties box on the right hand side change your background. Or are you talking about the area to each side of the page?
Either way take a look at this.
Stationary background