[css-color] Add a CMYK example.

Author: tabatkins

css-color/Overview.html

@@ -1745,6 +1745,21 @@ <h2 class="heading settled heading" data-level=7 id=cmyk-colors><span class=secn
 	the computed value of the <a class=css data-link-type=maybe href=#funcdef-device-cmyk title=device-cmyk()>device-cmyk()</a> function must be that RGBA color.
 	Otherwise, the computed value must be the fallback color.
 
+	<div class=example>
+		For example, the following colors are equivalent
+		(under the default conversion listed above):
+
+		<pre class=lang-css>  color: device-cmyk(0, 81%, 81%, 30%);
+  color: rgb(178, 34, 34);
+  color: firebrick;
+</pre>
+<p class=note>		Note: these colors might not match precisely 
+		if the browser knows a more precise conversion between CMYK and RGB colors.
+		It’s recommended that if authors use <strong>any</strong> CMYK colors in their document,
+		that they use <strong>only</strong> CMYK colors in their document
+		to avoid any color-matching difficulties.
+	</div>
+
 
 <h2 class="heading settled heading" data-level=8 id=modifying-colors><span class=secno>8 </span><span class=content>
 Modifying Colors: the <a class=css data-link-type=maybe href=#funcdef-color title=color()>color()</a> function</span><a class=self-link href=#modifying-colors></a></h2>

css-color/Overview.src.html

@@ -1682,6 +1682,23 @@ <h2 id='cmyk-colors'>
 	the computed value of the ''device-cmyk()'' function must be that RGBA color.
 	Otherwise, the computed value must be the fallback color.
 
+	<div class='example'>
+		For example, the following colors are equivalent
+		(under the default conversion listed above):
+
+		<pre class="lang-css">
+			color: device-cmyk(0, 81%, 81%, 30%);
+			color: rgb(178, 34, 34);
+			color: firebrick;
+		</pre>
+
+		Note: these colors might not match precisely 
+		if the browser knows a more precise conversion between CMYK and RGB colors.
+		It's recommended that if authors use <strong>any</strong> CMYK colors in their document,
+		that they use <strong>only</strong> CMYK colors in their document
+		to avoid any color-matching difficulties.
+	</div>
+
 
 <h2 id='modifying-colors'>
 Modifying Colors: the ''color()'' function</h2>