CSS glitch/misunderstanding

I’m new to using CSS to format pages. I grew up in the old wild and wooly days of font tags. 🙂
Anyway, working with WP has been a great learning experience, but now I’m stumped. My site is at http://dragonchasers.com/
If you go there you’ll see a green background for the headers, and a lighter green background down at the bottom of the page in the credits section. I want them to be the same color, and I’m not understanding why they aren’t.
CSS snippets:
#header {
background: #063;
font-family: Verdana, Arial, Helvetica, san-serif;
font-size: 24px;
font-weight: bold;
color: #fff;
margin: 0;
padding: 5px 1px 15px 10px;
}
.credit {
background: #063;
border-top: double 3px #aba;
color: #fff;
font-size: 11px;
margin: 10px 0 0 0;
padding: 3px;
text-align: center;
}
If I change the background value in .credit, the color of the bottom strip changes, so I’m sure I’m changing the correct value. But why aren’t they showing as the same color? Is there some kind of inheritance impacting the color of the bottom bar or something?
Any help would be greatly appreciated.