[FIX] web_timeline: Make colors attribute optional (#969)

web_timeline/__manifest__.py

@@ -4,7 +4,7 @@
 {
     'name': "Web timeline",
     'summary': "Interactive visualization chart to show events in time",
-    "version": "11.0.1.0.0",
+    "version": "11.0.1.0.1",
     'author': 'ACSONE SA/NV, '
               'Tecnativa, '
               'Monk Software, '

web_timeline/static/src/js/timeline_view.js

@@ -148,6 +148,8 @@ odoo.define('web_timeline.TimelineView', function (require) {
                         'value': temp.expressions[1].value
                     };
                 }).value();
+            } else {
+                this.colors = [];
             }
         },