[css-color-4] Corrected table of analogous components, alpha was missing, but described as analogous in prose #10254

Author: svgeesus

css-color-4/Overview.bs

@@ -4850,6 +4850,10 @@ Interpolating with Missing Components</h3>
 			<td>Opponent b</td>
 			<td>b</td>
 		</tr>
+		<tr>
+			<td>Alpha</td>
+			<td>alpha</td>
+		</tr>
 	</table>
 
 	Note: for the purposes of this classification,