diff --git a/tests/devx/conftest.py b/tests/devx/conftest.py
index eb56d74c..232edd78 100644
--- a/tests/devx/conftest.py
+++ b/tests/devx/conftest.py
@@ -4,6 +4,7 @@
 '''
 from __future__ import annotations
 import platform
+import re
 import signal
 import time
 from typing import (
@@ -216,6 +217,26 @@ def expect(
 PROMPT = r"\(Pdb\+\)"
 
 
+# Strip terminal color / ANSI-VT100 escape sequences so
+# substring matching against REPL + traceback output stays
+# robust to color leakage — Python 3.13's colored tracebacks,
+# `pdbp`'s pygments highlighting, etc. — even when
+# `PYTHON_COLORS=0` (set in the `spawn` fixture) isn't honored
+# by every renderer in the spawned subproc.
+# Regex per https://stackoverflow.com/a/14693789
+_ansi_re: re.Pattern = re.compile(
+    r'\x1B(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])'
+)
+
+
+def ansi_strip(text: str) -> str:
+    '''
+    Remove ANSI/VT100 escape sequences from `text`.
+
+    '''
+    return _ansi_re.sub('', text)
+
+
 def in_prompt_msg(
     child: SpawnBase,
     parts: list[str],
@@ -235,7 +256,7 @@ def in_prompt_msg(
     '''
     __tracebackhide__: bool = False
 
-    before: str = str(child.before.decode())
+    before: str = ansi_strip(str(child.before.decode()))
     for part in parts:
         if part not in before:
             if pause_on_false:
@@ -255,9 +276,9 @@ def in_prompt_msg(
     return True
 
 
-# TODO: todo support terminal color-chars stripping so we can match
-# against call stack frame output from the the 'll' command the like!
-# -[ ] SO answer for stipping ANSI codes: https://stackoverflow.com/a/14693789
+# NB: color-char stripping (so we can match against call-stack
+# frame output from the `ll` command and the like) is handled by
+# `ansi_strip()` applied inside `in_prompt_msg()` + below.
 def assert_before(
     child: SpawnBase,
     patts: list[str],
@@ -275,7 +296,8 @@ def assert_before(
         err_on_false=True,
         **kwargs
     )
-    return str(child.before.decode())
+    before: str = ansi_strip(str(child.before.decode()))
+    return before
 
 
 def do_ctlc(
diff --git a/tests/devx/test_debugger.py b/tests/devx/test_debugger.py
index d5fd759b..3c589bb2 100644
--- a/tests/devx/test_debugger.py
+++ b/tests/devx/test_debugger.py
@@ -1144,7 +1144,12 @@ def test_shield_pause(
             "('cancelled_before_pause'",  # actor name
             _repl_fail_msg,
             "trio.Cancelled",
-            "raise Cancelled._create()",
+            # trio >=0.30 raises via a multi-line
+            # `raise Cancelled._create(source=.., reason=..,
+            #  source_task=..)` (cancel-reason metadata), so
+            # match the open-paren form only, NOT the legacy
+            # bare `()`.
+            "raise Cancelled._create(",
 
             # we should be handling a taskc inside
             # the first `.port_mortem()` sin-shield!
@@ -1162,7 +1167,12 @@ def test_shield_pause(
             "('root'",  # actor name
             _repl_fail_msg,
             "trio.Cancelled",
-            "raise Cancelled._create()",
+            # trio >=0.30 raises via a multi-line
+            # `raise Cancelled._create(source=.., reason=..,
+            #  source_task=..)` (cancel-reason metadata), so
+            # match the open-paren form only, NOT the legacy
+            # bare `()`.
+            "raise Cancelled._create(",
 
             # handling a taskc inside the first unshielded
             # `.port_mortem()`.