Change bkd color for area containing site-title and site description in 2010

I want to make the background color of the entire header area black. And I don want any margins or padding on the left or the right. I am working with a child theme and I’ve managed to do most of what I want with changes to the wrapper, header, and site-title.

However, the background color of the area behind the site-title and site description remain white instead of black.

Setting the background color of #header to black only affects the top 30 px. Attempting to use a setting in #masthead, or #branding yields nothing.

I’m obviously missing something and I’d appreciate any help from those knowledgeable with the theme.

BTW – I have never seen the attribute “role” before – as in \ id=”branding” role=”banner” \. Is role an attribute of css or wordpress and where do I find more about it?

My site:
http://www.dj-group.org/private/wordpress1/