You can look at you style sheet (if it is in the file system) or you page (if it is just in the page) and see what it should look like. For example, for a simple change in color, I have listed under Additional CSS Definitions:
PHP Code:
.color1 {color:green}
Then, in my templates when I want to use that class, I would go:
PHP Code:
<span class="color1">This is text I want showed in green</span>
Or for more definitions in the class:
PHP Code:
.progtable {padding: 0px; background-image: url(images/background.png); background-repeat: repeat-x}
.progrow {padding: 0px; background-image: url(images/progress.png); background-repeat: repeat-x}
And in my plugin I have:
PHP Code:
$t="<table border=0 width=101 height=17 class='progtable'>";
$t.="<tr><td width=$percent class='progrow'>";
$t.=" </td><td border=0></td></tr></table>";