How do I remove the semi-opaque background?

I'm trying to figure out how to change the background-color of the main body of my theme. I have a background-image, and I would prefer that it completely shows through, and the posts float on the background-image, not on a semi-opaque background. I've created a child-theme, and I haven't been able to figure out the CSS code to change that element. http://laurelwreathlodge.org/wm/ Thanks!