Google Material chart Column Chart (Bar chart) cus

I want to draw a simple column chart in HTML-JavaScript using google chart.I have used Google materiel chart CDN to draw a column chart having 4 rows with 4 different colors.

I have tried plenty of options but nothing is working properly. when I have used the colors: ['#b0120a', '#004411', '#ffab91', '#004411'] only the first color is being displayed in all the 4 columns. I have also tried {role:'style'} but still not working.

<html>
<head>
    <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
    <script type="text/javascript">
      //google.charts.load('current', {'packages':['bar']});
      google.charts.load('visualization', '1', {packages: ['corechart', 'bar']});
      google.charts.setOnLoadCallback(drawChart);
      function drawChart() {

        /*var data = google.visualization.arrayToDataTable([
          ['Class', 'Total',{role: 'style'}],
          ['A', 10,'color: #b0120a'],
          ['B', 30,'color: #004411'],
          ['C', 20,'color: #ffab91'],
          ['D', 30,'color: #004411']
        ]);*/
        var data = google.visualization.arrayToDataTable([
          ['Class', 'Total'],
          ['A', 10],
          ['B', 30],
          ['C', 20],
          ['D', 30]
        ]);

        var options = {
          isStacked: true,
          title: 'Class wise total students',
          colors: ['#b0120a', '#004411', '#ffab91', '#004411'],
         };

        var chart = new google.charts.Bar(document.getElementById('columnchart_material'));
        chart.draw(data, google.charts.Bar.convertOptions(options));
      }
    </script>
</head>
<body>
<div id="columnchart_material" style="width: 100%; height: 100%;"></div>
</body>
</html>

The chart is like:

But I want 4 different colors for 4 columns. Thanks in advance.

Yaa, at last I made this one correct and exactly I wanted to be. Please see the code below, if you required sometime.

<html>
<head>
    <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
    <script type="text/javascript">
      google.charts.load('visualization', '1.1', {packages: ['corechart']});
      google.charts.setOnLoadCallback(drawChart);
      function drawChart() {    
        var data = google.visualization.arrayToDataTable([
          ['Class', 'Total',{role: 'style'}],
          ['A', 10,'color: #b0120a'],
          ['B', 30,'color: #004411'],
          ['C', 20,'color: #ffab91'],
          ['D', 30,'color: #004411']
        ]);

        var options = {
          isStacked: false,
          title: 'Class wise total students',
         };

        var chart = new google.visualization.ColumnChart(document.getElementById('columnchart_material'));
        chart.draw(data, options);
      }
    </script>
</head>
<body>
<div id="columnchart_material" style="width: 100%; height: 100%;"></div>
</body>
</html>

I need to changed the definition of chart here. From var chart = new google.charts.Bar(document.getElementById('columnchart_material')); to the modified one as var chart = new google.visualization.ColumnChart(document.getElementById('columnchart_material'));. It's working now. The chart is like ....