Hi Robert,
you can create a CSS style like the following and put this style to all headers.That way, you can control also the lower border lines of all headers, which make then a line.
When you put the header labels to not transparent, they also have a colored background.
label.table_header{
color: black;
background-color: #cbd7e2;
text-align: left;
border-style: solid;
margin: 0px 4px 2px 4px;
border-color: #cbd7e2 silver silver #cbd7e2;
border-width: 0px 1px 2px 0px;
}
For colors and their combinations, have a look at
http://www.colourlovers.com/palettesSame is true for the table rows, you can create similar styles for them and control every aspect of their appearance that way.