diff -r 6297fcddf912 Lib/idlelib/EditorWindow.py
--- a/Lib/idlelib/EditorWindow.py	Fri Apr 19 12:57:54 2013 -0400
+++ b/Lib/idlelib/EditorWindow.py	Fri Apr 19 21:30:32 2013 -0500
@@ -316,9 +316,6 @@
                     self.good_load = True
                     is_py_src = self.ispythonsource(filename)
                     self.set_indentation_params(is_py_src)
-                    if is_py_src:
-                        self.color = color = self.ColorDelegator()
-                        per.insertfilter(color)
             else:
                 io.set_filename(filename)
         self.ResetColorizer()
diff -r 6297fcddf912 Lib/idlelib/PyShell.py
--- a/Lib/idlelib/PyShell.py	Fri Apr 19 12:57:54 2013 -0400
+++ b/Lib/idlelib/PyShell.py	Fri Apr 19 21:30:32 2013 -0500
@@ -858,8 +858,6 @@
         text.bind("<<open-stack-viewer>>", self.open_stack_viewer)
         text.bind("<<toggle-debugger>>", self.toggle_debugger)
         text.bind("<<toggle-jit-stack-viewer>>", self.toggle_jit_stack_viewer)
-        self.color = color = self.ColorDelegator()
-        self.per.insertfilter(color)
         if use_subprocess:
             text.bind("<<view-restart>>", self.view_restart_mark)
             text.bind("<<restart-shell>>", self.restart_shell)
@@ -1063,6 +1061,11 @@
     def isatty(self):
         return True
 
+    def ispythonsource(self, filename):
+        # Override EditorWindow method so that the ColorDelegator
+        # always gets loaded.
+        return True
+
     def cancel_callback(self, event=None):
         try:
             if self.text.compare("sel.first", "!=", "sel.last"):