diff --git a/webroot/rsrc/css/layout/phabricator-source-code-view.css b/webroot/rsrc/css/layout/phabricator-source-code-view.css
--- a/webroot/rsrc/css/layout/phabricator-source-code-view.css
+++ b/webroot/rsrc/css/layout/phabricator-source-code-view.css
@@ -16,7 +16,7 @@
   white-space: pre-wrap;
   padding: 2px 8px 1px;
   width: 100%;
-  background: #ffffff;
+  background: {$diff.background};
 }
 
 .phabricator-source-line {