I do think that Azazul has a point, just give each body tag a class to change the background.
This is not related to your question, but I think you need to address the navigation which I noticed in your previous post. There is no rollover on the text and the menu does not dropdown on rollover. It requires 2 clicks from the small arrow to get to a page even if there is only one, and that is not very user friendly. :cry: