diff --git a/image/test/reftest/ImageDocument.css b/image/test/reftest/ImageDocument.css
index 5020dadd597..b4498109865 100644
--- a/image/test/reftest/ImageDocument.css
+++ b/image/test/reftest/ImageDocument.css
@@ -1,5 +1,5 @@
 body {
-  background: #222 url("chrome://global/skin/media/imagedoc-darknoise.png");
+  background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
   margin: 0;
 }
 
diff --git a/image/test/reftest/gif/ImageDocument.css b/image/test/reftest/gif/ImageDocument.css
index 5020dadd597..b4498109865 100644
--- a/image/test/reftest/gif/ImageDocument.css
+++ b/image/test/reftest/gif/ImageDocument.css
@@ -1,5 +1,5 @@
 body {
-  background: #222 url("chrome://global/skin/media/imagedoc-darknoise.png");
+  background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
   margin: 0;
 }
 
diff --git a/toolkit/themes/osx/global/media/TopLevelImageDocument.css b/toolkit/themes/osx/global/media/TopLevelImageDocument.css
index 2eb3f9d9671..e83c1c2c3d6 100644
--- a/toolkit/themes/osx/global/media/TopLevelImageDocument.css
+++ b/toolkit/themes/osx/global/media/TopLevelImageDocument.css
@@ -7,7 +7,7 @@
 
   body {
     color: #eee;
-    background: #222 url("chrome://global/skin/media/imagedoc-darknoise.png");
+    background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
   }
 
   img.decoded {
diff --git a/toolkit/themes/osx/global/media/TopLevelVideoDocument.css b/toolkit/themes/osx/global/media/TopLevelVideoDocument.css
index 423ee2bb80d..3060bf87e21 100644
--- a/toolkit/themes/osx/global/media/TopLevelVideoDocument.css
+++ b/toolkit/themes/osx/global/media/TopLevelVideoDocument.css
@@ -3,7 +3,7 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 body {
-  background: #333 url(data:image/png;base64,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);
+  background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
 }
 
 video {
diff --git a/toolkit/themes/osx/global/media/imagedoc-darknoise.png b/toolkit/themes/osx/global/media/imagedoc-darknoise.png
index 271dd5ebcfb..5c33e24d4c1 100644
Binary files a/toolkit/themes/osx/global/media/imagedoc-darknoise.png and b/toolkit/themes/osx/global/media/imagedoc-darknoise.png differ
diff --git a/toolkit/themes/windows/global/media/TopLevelImageDocument.css b/toolkit/themes/windows/global/media/TopLevelImageDocument.css
index 2eb3f9d9671..e83c1c2c3d6 100644
--- a/toolkit/themes/windows/global/media/TopLevelImageDocument.css
+++ b/toolkit/themes/windows/global/media/TopLevelImageDocument.css
@@ -7,7 +7,7 @@
 
   body {
     color: #eee;
-    background: #222 url("chrome://global/skin/media/imagedoc-darknoise.png");
+    background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
   }
 
   img.decoded {
diff --git a/toolkit/themes/windows/global/media/TopLevelVideoDocument.css b/toolkit/themes/windows/global/media/TopLevelVideoDocument.css
index 423ee2bb80d..3060bf87e21 100644
--- a/toolkit/themes/windows/global/media/TopLevelVideoDocument.css
+++ b/toolkit/themes/windows/global/media/TopLevelVideoDocument.css
@@ -3,7 +3,7 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 body {
-  background: #333 url(data:image/png;base64,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);
+  background-image: url("chrome://global/skin/media/imagedoc-darknoise.png");
 }
 
 video {
diff --git a/toolkit/themes/windows/global/media/imagedoc-darknoise.png b/toolkit/themes/windows/global/media/imagedoc-darknoise.png
index 271dd5ebcfb..5c33e24d4c1 100644
Binary files a/toolkit/themes/windows/global/media/imagedoc-darknoise.png and b/toolkit/themes/windows/global/media/imagedoc-darknoise.png differ