Google charts changing of a selected bar

I need to change the color of a selected bar after the chart has been loaded. The selected bar changes each time so I can't just specify in the style.

$(function() {
    google.load('visualization', '1', { 'callback': drawChart, 'packages':['corechart'] });

    function drawChart() {
      var data = google.visualization.arrayToDataTable([
        ["Element", "Density", { role: "style" } ],
        ["Copper", 8.94, "#b87333"],
        ["Silver", 10.49, "silver"],
        ["Gold", 19.30, "gold"],
        ["Platinum", 21.45, "color: #e5e4e2"]
      ]);

      var view = new google.visualization.DataView(data);
      view.setColumns([0, 1,
                       { calc: "stringify",
                         sourceColumn: 1,
                         type: "string",
                         role: "annotation" },
                       2]);

      var options = {
        title: "Density of Precious Metals, in g/cm^3",
        width: 600,
        height: 400,
        bar: {groupWidth: "95%"},
        legend: { position: "none" },
      };
      var chart = new google.visualization.ColumnChart(document.getElementById("columnchart_values"));
      chart.draw(view, options);


  }

})

I understand I can select a bar using:

var selectedItem = chart.getSelection()[0];

How would I change the color of "selectedItem" from here. Picture of chart if you are curious