--- a/hgext/split.py	Thu Nov 12 17:06:45 2020 -0800
+++ b/hgext/split.py	Fri Nov 13 09:41:49 2020 -0800
@@ -142,9 +142,14 @@
             header = _(
                 b'HG: Splitting %s. So far it has been split into:\n'
             ) % short(ctx.node())
-            for c in committed:
-                summary = cmdutil.format_changeset_summary(ui, c, b'split')
-                header += _(b'HG: - %s\n') % summary
+            # We don't want color codes in the commit message template, so
+            # disable the label() template function while we render it.
+            with ui.configoverride(
+                {(b'templatealias', b'label(l,x)'): b"x"}, b'split'
+            ):
+                for c in committed:
+                    summary = cmdutil.format_changeset_summary(ui, c, b'split')
+                    header += _(b'HG: - %s\n') % summary
             header += _(
                 b'HG: Write commit message for the next split changeset.\n'
             )