[css-color-4] oops dup ID

Author: svgeesus

css-color-4/Overview.bs

@@ -747,7 +747,7 @@ This section updates and replaces that part of CSS Object Model, section
 		<p>is the string "lab(56.2% 83.51 -3.79 / 0.93)"</p>
 	</div>
 
-	<h4 id="serializing-color-values">Serializing values of the ''color()'' function</h4>
+	<h4 id="serializing-color-function-values">Serializing values of the ''color()'' function</h4>
 
 	The serialized form of ''color()'' values
 	is derived from the [=computed value=]