Shell was not colorizing due to bug introduced at r57998, Bug 1586.
diff --git a/Lib/idlelib/PyShell.py b/Lib/idlelib/PyShell.py
index 097818f..9962894 100644
--- a/Lib/idlelib/PyShell.py
+++ b/Lib/idlelib/PyShell.py
@@ -811,6 +811,8 @@
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)