Index: src/wp-admin/css/common.css
===================================================================
--- src/wp-admin/css/common.css	(revision 50803)
+++ src/wp-admin/css/common.css	(working copy)
@@ -878,7 +878,8 @@
 #media-items a.delete,
 #media-items a.delete-permanently,
 #nav-menu-footer .menu-delete,
-#delete-link a.delete {
+#delete-link a.delete,
+a#remove-post-thumbnail {
 	color: #b32d2e;
 }
 
@@ -895,7 +896,8 @@
 #media-items a.delete:hover,
 #media-items a.delete-permanently:hover,
 #nav-menu-footer .menu-delete:hover,
-#delete-link a.delete:hover {
+#delete-link a.delete:hover,
+a#remove-post-thumbnail:hover {
 	color: #b32d2e;
 	border: none;
 }