yellow was so jarring, wikipedia says this is one

of the most calming colors.

index.html

@@ -18,7 +18,7 @@
     }
 
     #app-vertical {
-      background-color: yellow;
+      background-color: #AFEEEE;
       display: -webkit-box;
       -webkit-box-flex: 1;
       -webkit-box-orient: vertical;