CiviCRM Community Forums (archive)

You may need to use an explicit style attribute on the enclosing div. Something like this:

<div style="background-color: #cccccc;">

(you'll use the "Source" button in the HTML / WYSIWYG editor to add this).

If this isn't working, you might want to paste the HTML / CSS code you're using here so folks can potentially give your more help.