You've posted your question in the forums for Adobe BrowserLab, a cross-browser testing tool. Since your question is about Adobe Illustrator, I'm moving your question to the appropriate forum here: http://forums.adobe.com/community/illustrator/illustrator_general
Best of luck,
If you like you may direct select the text box (only) of Area Type and give it a fill colour.
This will entail some adjustments (indent etc.) as to how the type sits within the box.
It is usually simpler to draw a coloured rectangle behind the type.