Adding Image behind new posts on homepage

Hello,   I was wondering if it was possible to add an image/ different colour behind the newpost excerpts + thumbnails that come up on the home page. Something like whole foods has done: http://www.wholefoodsmarket.com/blog/whole-story?page=1 On their blog - their new posts and actually posts have a paper-like background.   The blog is www.truthinablog.organika.ca   Thank you, Sasha