What I mean is through using firebug you can find and target the specific css classes and ids you would need to edit. Say if you can’t figure out how to change the colour of a specific title on your website all you need to do it right click on it in firefox, click “inspect element in firebug” and firbug will tell you it’s properties. For example, it might be <h1 class=”mainTitle”>the title</h1>. Then you know that if you go to your css in your editor and type:
.mainTitle {
color: "red";
}
Then the colour of .mainTitle will be red. You can do that with any element, you can even change the colour directly in firebug to preview what it will look like before going and making the change in your editor.