Index: _source/plugins/colorbutton/plugin.js
===================================================================
--- _source/plugins/colorbutton/plugin.js	(revision 3674)
+++ _source/plugins/colorbutton/plugin.js	(working copy)
@@ -66,8 +66,15 @@
 
 					panel.hide();
 
-					var style = new CKEDITOR.style( config['colorButton_' + type + 'Style'], { color : color || '#000' } );
+					var removeColor = null;
+					if ( !color )
+					{
+						var element = editor.getSelection().getStartElement();
+						removeColor = element .getComputedStyle( type == 'back' ? 'background-color' : 'color' );
+					}
 
+					var style = new CKEDITOR.style( config[ 'colorButton_' + type + 'Style' ], { color : color || removeColor } );
+
 					editor.fire( 'saveSnapshot' );
 					if ( color )
 						style.apply( editor.document );