Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 5486)
+++ /CKEditor/trunk/CHANGES.html	(revision 5487)
@@ -89,4 +89,5 @@
 		<li><a href="http://dev.fckeditor.net/ticket/5573">#5573</a> : SCAYT move cursor position after insert element into marked word text.</li>
 		<li><a href="http://dev.fckeditor.net/ticket/5546">#5546</a> : SCAYT interferes with undo/redo commands.</li>
+		<li><a href="http://dev.fckeditor.net/ticket/5676">#5676</a> : Make color buttons use RRGGBB instead of RGB for better compatibility with IE.</li>
 		<li>Updated the following language files:<ul>
 			<li><a href="http://dev.fckeditor.net/ticket/5432">#5432</a> : Dutch;</li>
Index: /CKEditor/trunk/_source/plugins/colorbutton/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/colorbutton/plugin.js	(revision 5486)
+++ /CKEditor/trunk/_source/plugins/colorbutton/plugin.js	(revision 5487)
@@ -141,6 +141,7 @@
 				// The data can be only a color code (without #) or colorName + color code
 				// If only a color code is provided, then the colorName is the color with the hash
+				// Convert the color from RGB to RRGGBB for better compatibility with IE and <font>. See #5676
 				if (!parts[1])
-					colorName = '#' + colorName;
+					colorName = '#' + colorName.replace( /^(.)(.)(.)$/, '$1$1$2$2$3$3' );
 
 				var colorLabel = editor.lang.colors[ colorCode ] || colorCode;