Colored Google Maps LatLng Bounds

Proof that the bug report is right: Issue #4813 https://code.google.com/p/gmaps-api-issues/issues/detail?id=4813&q=apitype%3AJavascript3%20type%3ADefect%20bounds&sort=-stars&colspec=ID%20Type%20Status%20Introduced%20Fixed%20Summary%20Internal%20Stars

HTML

<script src="http://maps.google.com/maps/api/js?sensor=false&amp;libraries=geometry&amp;.js"></script>
<div id="map"></div>

CSS

html, body, #map {
    margin: 0;
    padding: 0;
    height: 100%;
    width: 100%;
}

JavaScript

"use strict";

var Figline = new google.maps.LatLng( 43.637527, 11.449750 ),
map = new google.maps.Map( 
  document.getElementById( 'map' ),
  {
    zoom      : 13,
    center    : Figline,
    mapTypeId : google.maps.MapTypeId.ROADMAP,

    panControl         : false,
    zoomControl        : false,
    scaleControl       : false,
    streetViewControl  : false,
    overviewMapControl : false
  }
),
rectangleABounds = new google.maps.LatLngBounds(
  new google.maps.LatLng( 43.67, 11.40), //sw
  new google.maps.LatLng( 43.63, 11.47) //ne
),

rectangleBBounds = new google.maps.LatLngBounds(
  new google.maps.LatLng( 43.72, 11.45), //sw
  new google.maps.LatLng( 43.68, 11.50) //ne
),

rectangleCBounds = new google.maps.LatLngBounds(
  new google.maps.LatLng( 43.71, 11.44), //sw
  new google.maps.LatLng( 43.67, 11.49) //ne
),

rectangleDBounds = new google.maps.LatLngBounds(
  new google.maps.LatLng( 43.66, 11.42), //sw
  new google.maps.LatLng( 43.65, 11.44) //ne
),


rectangleA = new google.maps.Rectangle( {
  strokeColor   : 'red',
  strokeOpacity : 1,
  strokeWeight  : 8,
  fillOpacity   : 0,
  map           : map,
  bounds        : rectangleABounds
} ),

rectangleB = new google.maps.Rectangle( {
  strokeColor   : 'blue',
  strokeOpacity : 1,
  strokeWeight  : 8,
  fillOpacity   : 0,
  map           : map,
  bounds        : rectangleBBounds
} ),

rectangleC = new google.maps.Rectangle( {
  strokeColor   : 'purple',
  strokeOpacity : 1,
  strokeWeight  : 8,
  fillOpacity   : 0,
  map           : map,
  bounds        : rectangleCBounds
} ),

rectangleD = new google.maps.Rectangle( {
  strokeColor   : 'tan',
  strokeOpacity : 1,
  strokeWeight  : 8,
  fillOpacity   : 0,
  map           : map,
  bounds        : rectangleDBounds
} ),

boundsf = rectangleABounds.union(rectangleBBounds),
boundsf = boundsf.union(rectangleCBounds),

bounds = new google.maps.LatLngBounds(new google.maps.LatLng(43.67, 11.40), new google.maps.LatLng(43.63, 11.47)),
UUU = bounds.union(new...