Index: /trunk/src/org/openstreetmap/josm/gui/layer/CustomizeColor.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/layer/CustomizeColor.java	(revision 19434)
+++ /trunk/src/org/openstreetmap/josm/gui/layer/CustomizeColor.java	(revision 19435)
@@ -87,4 +87,5 @@
             colorLayers.forEach(l -> l.setColor(c.getColor()));
             break;
+        case JOptionPane.CLOSED_OPTION:
         case JOptionPane.NO_OPTION:
             return;