diff --git a/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
index 288d5e4..0d27475 100644
--- a/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -435,7 +435,7 @@ ul.links a.is-active {
   text-decoration: none;
 }
 .tabs a.is-active {
-  background-color: #eee;
+  background-color: #fff;
 }
 .tabs a:focus,
 .tabs a:hover {