diff --git a/Lib/idlelib/ColorDelegator.py b/Lib/idlelib/ColorDelegator.py
index e4ccb4258c6..61e2be47c7e 100644
--- a/Lib/idlelib/ColorDelegator.py
+++ b/Lib/idlelib/ColorDelegator.py
@@ -51,6 +51,10 @@ class ColorDelegator(Delegator):
             self.config_colors()
             self.bind("<<toggle-auto-coloring>>", self.toggle_colorize_event)
             self.notify_range("1.0", "end")
+        else:
+            # No delegate - stop any colorizing
+            self.stop_colorizing = True
+            self.allow_colorizing = False
 
     def config_colors(self):
         for tag, cnf in self.tagdefs.items():
diff --git a/Misc/NEWS b/Misc/NEWS
index 0bf63e28a41..087fb2020cd 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -1015,6 +1015,8 @@ _ Issue #17385: Fix quadratic behavior in threading.Condition.  The FIFO
 IDLE
 ----
 
+- Issue #17613: Prevent traceback when removing syntax colorizer in IDLE.
+
 - Issue #1207589: Backwards-compatibility patch for right-click menu in IDLE.
 
 - Issue #16887: IDLE now accepts Cancel in tabify/untabify dialog box.