--- a/ImageEditor.st	Thu Jun 20 17:57:40 2013 +0200
+++ b/ImageEditor.st	Fri Jun 21 00:50:10 2013 +0200
@@ -5182,7 +5182,7 @@
             ditherColors := ditherColors , moreColors.
         ].
     ] ifFalse:[
-self halt.
+        self halt:'unhandled dither color setup'.
     ].
 
     self withExecuteCursorDo:[