[Digital Jedi]

I personally would do that by setting the left or right margins to about a pixel or so. Something like margin-left:2px;. That would put a space beside every menu item, which will be the background color of the navbar. Try something like this in the additional CSS field:

margin-left:2px; /* This puts the space beside each item with this class. */
padding:0 6px 0 6px; /* This sets the spacing inside the items with this class clockwise from the top. */
white-space:nowrap; /* This makes certain the text of the items stays on one line */