fix background clolor

_posts/2016-09-13-code-for-ruhr.markdown

@@ -1,7 +1,7 @@
 ---
 layout: post
 title: "Code for Ruhrgebiet"
-date: 2016-09-13 10:23:42
+date: 2016-09-13 08:23:42
 categories: Code for Ruhr
 ---