title: change the color of the polyline in DirectionsRenderer
body: <p>i've integrated a map and i want to display the route directions between two locations.
  everything is working fine and the directions is displayed perfectly ,
  but i want to change the color of the <code>Polyline</code> direction ,i've tried this code like the documentation says : </p>
  
  <pre><code>//polyline options
      var pOptions = {
              map: map,
              strokeColor: "#2249a3",
              strokeOpacity: 0.9 ,
              strokeWeight: 12,
              z-index: 99
      };
      logJava(polylineOptions);
  
      //directionsRenderer options
      var mDirectionsRendererOptions = {
              map: map,
              suppressMarkers: true,
              suppressInfoWindows: true,
              polylineOptions: pOptions
      };
  
      logJava(mDirectionsRendererOptions);
  
      directionsDisplay = new google.maps.DirectionsRenderer(mDirectionsRendererOptions);
  </code></pre>
  
  <p>but when i add this code , it stops the map , and it displays nothing, when i comment it , everything is working fine . </p>
  
  <p>what is wrong with this code, and how to change the color of the polyline with <strong>google maps javascript api v3</strong> ?</p>
  
  <p>Thanks in advance,</p>