EXAMPLE
Run 
<!DOCTYPE html>
<html>

<head>
	<title>The empty-cells function in CSS</title>
	<style type="text/css">
		.table_1 {
		  empty-cells: show;
		  background-color: skyblue;
		}
		
		.table_2 {
		  empty-cells: show;
		  background-color: pink;
		}
		
		td,
		th {
		  border: 1px solid gray;
		  padding: 0.5rem;
		}
	</style>
</head>

<body>
	<table class="table_1">
		<tr>
			<td>RED</td>
			<td>YELLOW</td>
		</tr>
		<tr>
			<td>PURPLE</td>
			<td></td>
		</tr>
	</table>
	<br>
	<table class="table_2">
		<tr>
			<td>BLACK</td>
			<td>YELLOW</td>
		</tr>
		<tr>
			<td>PURPLE</td>
			<td></td>
		</tr>
	</table>
</body>

</html>