Do you have the CSS upgrade? Otherwise you won't be able to do what you want.
Assuming you do have it, then you don't need to use the custom header/background features, so you'll have to reset them. Once you've done that, paste this code in your CSS editor (I'm using the same header and background images):
body {background: #85C5A3 url(http://thespringbride.files.wordpress.com/2010/04/0c9e004d4.jpg) 0 0;}
#branding {
background: #fff url(http://thespringbride.files.wordpress.com/2010/04/cropped-georgia-okeeffe-white-rose-with-larkspur6.jpg) 0 0 no-repeat;
height: 198px;
width: 940px;
}
#branding img {display: none;}
#site-title {margin: 20px;}
#access {
background: #003;
}
.menu a{
font-family: "Times New";
color: #fff !important;
}
.menu a:hover {
background: #00f !important;
}
The values of the "color" attributes in the "#access", ".menu ul a" and ".menu ul a:hover" selectors are just for sample purposes; of course, you'll need to change them to whatever colors you want. Same thing goes for the "font-family" property of the ".menu a" selector.
It's highly recommended to not paste the whole CSS in the CSS Editor but just the changes/additions you're making to the theme. I'd recommend you reading this for more info:
http://csswiz.wordpress.com/2009/10/15/if-you-have-the-wp-com-css-upgrade/
HTH
timethief
