diff --git a/test/color.rules.t b/test/color.rules.t
index efc927e91..48228c6f2 100755
--- a/test/color.rules.t
+++ b/test/color.rules.t
@@ -126,7 +126,8 @@ class TestColorRules(TestCase):
     def test_due_anhourago(self):
         """Overdue color rule from an hour ago."""
         code, out, err = self.t('/anhourago/ info')
-        self.assertIn('\x1b[34m', out)
+        # Match 4-bit or 8-bit blue color code
+        self.assertRegex(out, '\x1b\[(38;5;4|34)m')
 
     def test_due_tomorrow(self):
         """Due tomorrow color rule."""