Fix background color of dialogs on Tinyboard.

src/main/Main.coffee

@@ -244,9 +244,9 @@ Main =
         $.rm Main.bgColorStyle
       else
         # Determine proper background color for dialogs if 4chan is using a special stylesheet.
-        div = $.el 'div',
-          className: 'reply'
-        div.style.cssText = 'position: absolute; visibility: hidden;'
+        div = Site.bgColoredEl()
+        div.style.position = 'absolute';
+        div.style.visibility = 'hidden';
         $.add d.body, div
         bgColor = window.getComputedStyle(div).backgroundColor
         $.rm div

src/site/SW.tinyboard.coffee

@@ -45,6 +45,9 @@ SW.tinyboard =
         $
       ///
 
+  bgColoredEl: ->
+    $.el 'div', className: 'post reply'
+
   parseNodes: (post, nodes) ->
     # Add vichan's span.poster_id around the ID if not already present.
     return if nodes.uniqueID

src/site/SW.yotsuba.coffee

@@ -52,6 +52,9 @@ SW.yotsuba =
         $
       ///
 
+  bgColoredEl: ->
+    $.el 'div', className: 'reply'
+
   isThisPageLegit: ->
     # not 404 error page or similar.
     location.hostname is 'boards.4chan.org' and