[flexcoders] Using CSS with custom item renderers

[Amy]

Hi, all;

I'm trying to style a custom item renderer.  I've called 
it "TestRenderer."  It's basically a canvas with a label in it.  This 
is the style declaration:

TestRenderer{
                backgroundColor: #FF0000;
                backgroundAlpha:0;
                fontSize: 16;
        }

This is the mxml declaration:

        <mx:List id="weekList" width="200"  
rowCount="{weekList.dataProvider.length}" 
itemRenderer="com.magnoliamultimedia.views.TestRenderer" 
minWidth="0"/>

I am expecting to see an item renderer with an ugly bright red 
background.  Instead, I see no background.  The font size _does_ 
change, though.

Can anyone give me a clue as to why my component style isn't changing?

Thanks;

Amy