Index: src/wp-includes/css/editor.css
===================================================================
--- src/wp-includes/css/editor.css	(revision 27190)
+++ src/wp-includes/css/editor.css	(working copy)
@@ -3,9 +3,10 @@
 ------------------------------------------------------------------------------*/
 
 /* TinyMCE widgets/containers */
-
 .mce-container,
-.mce-widget {
+.mce-container *,
+.mce-widget,
+.mce-widget * {
 	color: inherit;
 	font-family: inherit;
 }
@@ -55,14 +56,14 @@
 .mce-window .mce-window-head .mce-close:before {
 	font: normal 20px/2 'dashicons';
 	text-align: center;
-	color: #888;
+	color: #666;
 	width: 40px;
 	height: 40px;
 	display: block;
 }
 
 .mce-window .mce-window-head .mce-close:hover:before {
-	color: #555;
+	color: #2ea2cc;
 }
 
 .mce-window .mce-window-head .mce-dragh {