diff --git a/pylons_app/lib/app_globals.py b/pylons_app/lib/app_globals.py
--- a/pylons_app/lib/app_globals.py
+++ b/pylons_app/lib/app_globals.py
@@ -21,3 +21,4 @@ class Globals(object):
         self.baseui = make_ui('hgwebdir.config')
         self.paths = self.baseui.configitems('paths')
         self.base_path = self.paths[0][1].replace('*', '')
+        self.changeset_annotation_colors = {}