You now have the ability to edit the color of the "new post" background through the color configurator.
Also, there's a cheap hack for someone, I forget who it was, but you CAN specify an image for the backgrounds of things.
So, lets say, for the "Alternating List Color #2" you want it to actually be an image. Lets say you want "http://www.poopinashoe.com/settings/pias/files/back.jpg" to be the background image for that.
When you would do in the Color Configurator is type: