This diagram shows a small table with three transparent cells and illustrates how their final background is determined.
The table consists of two rows. Four (labeled) cells lie in the first row, but the second cell spans the first and second row. The first, third, and fourth cells of the second row are "empty".
Each non-empty cell has a red background and a double black border. Each empty cell has the table's background color (specified as #ff0) as its own.