diff --git a/addons/web/static/src/js/views/form_relational_widgets.js b/addons/web/static/src/js/views/form_relational_widgets.js
index 73e68fedf9c..428a2fe4758 100644
--- a/addons/web/static/src/js/views/form_relational_widgets.js
+++ b/addons/web/static/src/js/views/form_relational_widgets.js
@@ -1467,17 +1467,18 @@ var FieldMany2ManyTags = AbstractManyField.extend(common.CompletionFieldMixin, c
         }
     },
     open_color_picker: function(ev){
+        this.mutex.exec(function(){
+            if (this.fields.color) {
+                this.$color_picker = $(QWeb.render('FieldMany2ManyTag.colorpicker', {
+                    'widget': this,
+                    'tag_id': $(ev.currentTarget).data('id'),
+                }));
 
-        if (this.fields.color) {
-            this.$color_picker = $(QWeb.render('FieldMany2ManyTag.colorpicker', {
-                'widget': this,
-                'tag_id': $(ev.currentTarget).data('id'),
-            }));
-
-            $(ev.currentTarget).append(this.$color_picker);
-            this.$color_picker.dropdown('toggle');
-            this.$color_picker.attr("tabindex", 1).focus();
-        }
+                $(ev.currentTarget).append(this.$color_picker);
+                this.$color_picker.dropdown('toggle');
+                this.$color_picker.attr("tabindex", 1).focus();
+            }
+        }.bind(this));
     },
     close_color_picker: function(){
         this.$color_picker.remove();