Change/add individual post container

Hello,

I am trying to add a container to each post on my blog page…not he page background or blog roll background…but rather a separate container for each post so it pops off the page a little better…any help would be greatly appreciated. My site is underthefro.com. I would like to do something similar to the perezhilton.com site. The page background is pink, and the content area bg is a lighter pink…but each post appears inside a white box…thanks again