Style Mgr: Border-top, Border-bottom
 

I am designing my first custom skin and I'm trying to replicate the (admittedly subtle) 3-D border in my HTML prototype as below:

http://www.bronzino.net/blab/graphics/borders.gif

I am trying to do this in Style Manager's Main CSS "Table Border" interface. This is how I have it set right now:

Background: #E6EBE0
Extra CSS Attributes:
border-bottom-color: #8B9F80;
border-top-color: #B0BF9D;
border-left-color: #B0BF9D;

Only the single color indicated as "Background" displays, so I assume I am doing something wrong either in syntax or using the wrong interface. Can anyone suggest how I can achieve this look? I searched here for a thread, found one, but no one responded to it. I hope that doesn't mean no answer exists! :)