diff --git a/client/js/views/tag_categories_view.js b/client/js/views/tag_categories_view.js
index 51e3d390..7e1000d0 100644
--- a/client/js/views/tag_categories_view.js
+++ b/client/js/views/tag_categories_view.js
@@ -135,6 +135,7 @@ class TagCategoriesView extends events.EventTarget {
     }
 
     _evtColorChange(e, rowNode) {
+        e.target.value = e.target.value.toLowerCase();
         rowNode._tagCategory.color = e.target.value;
     }