Hola!
Ahí va mi propuesta de resolución del ejercicio CU01020D
<!DOCTYPE html>
<html>	
	<head>
		<meta charset="utf-8">
		<meta name="keywords" content="palabras clave">
		<meta name="description" content="Portal básico">
		<link rel="stylesheet" type="css/text" href="Ejer1020.css">
		<title>Portal Básico</title>
	</head>
	<body>
		<div id="page">
			<!--Cabecera-->
			<div id="header">
				
			</div>
			<!--Contenedor-->
			<div id="wrapper">
				<!--Menú-->
				<div id="menu">
				
				</div>
				<!--Fin menú-->
				<!--Cuerpo-->
				<div id="body">
					<table>
						<tr>
							<th>Color RGB 178,34,34</th>
							<td>T. 0.1</td>
							<td>T. 0.2</td>
							<td>T. 0.3</td>
							<td>T. 0.4</td>
							<td>T. 0.5</td>
							<td>T. 0.6</td>
							<td>T. 0.7</td>
							<td>T. 0.8</td>
							<td>T. 0.9</td>
							<td>T. 1</td>
						</tr>
						<tr>
							<th>Color RGB 218,165,32</th>
							<td>T. 0.1</td>
							<td>T. 0.2</td>
							<td>T. 0.3</td>
							<td>T. 0.4</td>
							<td>T. 0.5</td>
							<td>T. 0.6</td>
							<td>T. 0.7</td>
							<td>T. 0.8</td>
							<td>T. 0.9</td>
							<td>T. 1</td>
						</tr>
					</table>
				</div>
				<!--Fin cuerpo-->
			</div>
			<!--Fin contenedor-->
			<div id="footer">
			
			</div>
		</div>
	</body>
</html>
Y el archivo css es este
/*Ejercicio 1020D*/
table {border:1px solid}
table th{background-color:antiquewhite;}
table tr:first-child td:nth-child(2){background-color:rgba(178,34,34,0.1);}
table tr:first-child td:nth-child(3){background-color:rgba(178,34,34,0.2);}
table tr:first-child td:nth-child(4){background-color:rgba(178,34,34,0.3);}
table tr:first-child td:nth-child(5){background-color:rgba(178,34,34,0.4);}
table tr:first-child td:nth-child(6){background-color:rgba(178,34,34,0.5);}
table tr:first-child td:nth-child(7){background-color:rgba(178,34,34,0.6);}
table tr:first-child td:nth-child(8){background-color:rgba(178,34,34,0.7);}
table tr:first-child td:nth-child(9){background-color:rgba(178,34,34,0.8);}
table tr:first-child td:nth-child(10){background-color:rgba(178,34,34,0.9);}
table tr:first-child td:nth-child(11){background-color:rgba(178,34,34,1);}
table tr:first-child+tr td:nth-child(2){background-color:rgba(218,165,32,0.1);}
table tr:first-child+tr td:nth-child(3){background-color:rgba(218,165,32,0.2);}
table tr:first-child+tr td:nth-child(4){background-color:rgba(218,165,32,0.3);}
table tr:first-child+tr td:nth-child(5){background-color:rgba(218,165,32,0.4);}
table tr:first-child+tr td:nth-child(6){background-color:rgba(218,165,32,0.5);}
table tr:first-child+tr td:nth-child(7){background-color:rgba(218,165,32,0.6);}
table tr:first-child+tr td:nth-child(8){background-color:rgba(218,165,32,0.7);}
table tr:first-child+tr td:nth-child(9){background-color:rgba(218,165,32,0.8);}
table tr:first-child+tr td:nth-child(10){background-color:rgba(218,165,32,0.9);}
table tr:first-child+tr td:nth-child(11){background-color:rgba(218,165,32,1);}
No se si existe una forma más corta de hacerlo.
Vuestra página es cojonuda.
Un saludo!
Gracias!