diff -r 000000000000 -r 6474c204b198 toolkit/themes/osx/global/media/TopLevelImageDocument.css
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/themes/osx/global/media/TopLevelImageDocument.css	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+@media not print {
+  /* N.B.: Remember to update ImageDocument.css in the tree or reftests may fail! */
+
+  body {
+    color: #eee;
+    background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
+  }
+
+  img.decoded {
+    background: hsl(0,0%,90%) url("chrome://global/skin/media/imagedoc-lightnoise.png");
+    color: #222;
+  }
+}