‘background-color’ (and related properties) on table elements are applied as if the table is made up of multiple layers. From back to front, the ‘layers’ are derived from: <CSS:table>; <CSS:table-column> with a ‘number-columns-spanned’ value greater than 1; <CSS:table-column> with a ‘number-columns-spanned’ value greater than 1; <CSS:table-column>; <CSS:table-header>, <CSS:table-body>, and <CSS:table-footer> (which do not overlap); <CSS:table-row>; and <CSS:table-cell>. A layer is visible only when all of the layers above it have a transparent background.
‘background-color’ is specified on most of the elements in the following table. Each element type has a different value. The property is omitted on some elements to allow the color from underlying layers to be seen. The <CSS:table-body> background is transparent to allow the background colors from <CSS:table> and <CSS:table-column> to be seen.
The background layers in this example are simulated using PDF layers. If you are viewing this in a PDF viewer that supports layers, you can enable and disable individual layers to see the effect of each one.