You can change the CSS file manually...but you'll need to know what css class to change..

I'd get the firebug addon for firefox...use the inspector tool and hover over which element you want to change...then you will see its CSS class name and any css property styles applied to it in the right panel...

Then open up the CSS file, search for that class name, and change the background property:

.classname { background:#F5F5F5; }

That should do the trick. Look in the /themes/<theme name> folder if your having trouble finding the right css file to edit, usually named style.css.

Firebug works great. There is (was) also a color sampler plugin for Firefox (mine got lost with the last FireFox upgrade.) All you had to do was right click in the browser window, then click on the eyedropper. Then you could use the eyedropper to get the hex color codes for various spots in the browser window.

Harrison