ok, that makes sense.
The fastest way I've found to locate what CSS needs to be changed is to use the Firefox Firebug extension or the Chrome Developer Tools which let you pinpoint what CSS is being applied to any element on the page.
If you're newbie to all this you might find that confusing. If you've learned your way around a bit you could try it yourself. Basically you point at the line within the tool and see what CSS is applied to it. It tells you the line number on which its applied. You can change it in the browser to see what effect that change will have. Then when you get the effect you are looking for you make it permanent by putting it in the stylesheet.
The first thing I'd try is finding that page element and assigning a
You may have to add a class name to the element that holds the line (could be an html img tag or could be used as a background image in the stylesheet, depending on how the theme is coded).