have sitewrapper would like to add a content wrapper

[acharme]

I have centered my shop with a sitewrapper. Now I would like to wrap the center contents in a different color. (column left and right are excluded) Just the middle contents where (for example) the privacy policy text is, or the category images. I made a content wrapper in the stylesheet, and dropped it in several places both in application_top and index.php. The best I got was a box that hid the middle content. If someone could help me see where I am messing up, I would appreciate...