Index: src/wp-admin/css/forms.css
===================================================================
--- src/wp-admin/css/forms.css	(revision 46288)
+++ src/wp-admin/css/forms.css	(working copy)
@@ -340,6 +340,19 @@
 	box-shadow: none;
 }
 
+.wp-admin select.disabled,
+.wp-admin select:disabled {
+	color: #a0a5aa !important;
+	border-color: #ddd !important;
+	background-color: #f7f7f7 !important;
+	/* The SVG is arrow-down-alt2 from Dashicons. */
+	background-image: url('data:image/svg+xml;charset=US-ASCII,%3Csvg%20width%3D%2220%22%20height%3D%2220%22%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%3E%3Cpath%20d%3D%22M5%206l5%205%205-5%202%201-7%207-7-7%202-1z%22%20fill%3D%22%23a0a5aa%22%2F%3E%3C%2Fsvg%3E') !important;
+	box-shadow: none !important;
+	text-shadow: 0 1px 0 #fff !important;
+	cursor: default;
+	transform: none !important;
+}
+
 .wp-admin .button-cancel {
 	padding: 0 5px;
 	line-height: 2;