Dreamweaver CS5- How to have your background in the middle a different color then the rest of your background?

Im designing a website and I wanted to know how to have a center that is the same when you click on different links. Here are some examples...



https://www.lafitness.com/Pages/whyjoin.aspx



http://www.roomstogo.com/index.cfm?fuseaction=searchResults%26amp;categoryName=category_root%26amp;category=75%26amp;subCategoryName=Home%20Entertainment



http://www.redlobster.com/



all of these websites have a center that goes to the bottom of the page and every time you click on a different link, the tabs and center background and outline stay the same, with just the information changing. any help is appreciatedDreamweaver CS5- How to have your background in the middle a different color then the rest of your background?
http://www.webdesignerwall.com/tutorials鈥?/a>