diff --git a/theme/oceanblue/styles_color.css b/theme/oceanblue/styles_color.css
index dc28e62bac1..ac436eb41eb 100644
--- a/theme/oceanblue/styles_color.css
+++ b/theme/oceanblue/styles_color.css
@@ -79,7 +79,7 @@ div.header {
 }
 
 table.formtable tbody th {
-  background-color: none;
+  background-color: transparent;
 }
 
 .highlight {
@@ -710,7 +710,7 @@ table.message_search_results td {
   background-color: #FFD991;
 }
 #mod-forum-discuss .forumpost {
-  background-color: none;
+  background-color: transparent;
 }
 
 #mod-forum-discuss .forumpost.unread .content {