Add support for background color app setting

tailbone/subscribers.py

@@ -124,6 +124,9 @@ def before_render(event):
         renderer_globals['messaging_enabled'] = request.rattail_config.getbool(
             'tailbone', 'messaging.enabled', default=False)
 
+        renderer_globals['background_color'] = request.rattail_config.get(
+            'tailbone', 'background_color')
+
 
 def add_inbox_count(event):
     """

tailbone/templates/base.mako

@@ -11,6 +11,12 @@
     ${base_meta.favicon()}
     ${self.header_core()}
 
+    % if background_color:
+        <style type="text/css">
+          body { background-color: ${background_color}; }
+        </style>
+    % endif
+
     % if not request.rattail_config.production():
         <style type="text/css">
           body { background-image: url(${request.static_url('tailbone:static/img/testing.png')}); }

tailbone/views/settings.py

@@ -163,7 +163,7 @@ class AppSettingsView(View):
         for setting in self.iter_known_settings():
             value = form.validated[setting.node_name]
             if value is colander.null:
-                value = None
+                value = ''
             self.save_setting_value(setting, value)
 
     def iter_known_settings(self):