diff --git a/wp-admin/css/colors-classic.css b/wp-admin/css/colors-classic.css
index 27d6e2450..bca78472d 100644
--- a/wp-admin/css/colors-classic.css
+++ b/wp-admin/css/colors-classic.css
@@ -615,6 +615,11 @@ input.readonly, textarea.readonly {
 	border-color: #dfdfdf;
 }
 
+.widget,
+.postbox {
+	background-color: #fff;
+}
+
 .ui-sortable .postbox h3 {
 	color: #093e56;
 }
diff --git a/wp-admin/css/colors-fresh.css b/wp-admin/css/colors-fresh.css
index 16f7ea184..82ae6f955 100644
--- a/wp-admin/css/colors-fresh.css
+++ b/wp-admin/css/colors-fresh.css
@@ -614,7 +614,7 @@ input.readonly, textarea.readonly {
 
 .widget,
 .postbox {
-	background-color: #FFF;
+	background-color: #fff;
 }
 
 .ui-sortable .postbox h3 {