Using column chart to create background fills

HTML

<script src="http://www.amcharts.com/lib/3/amcharts.js"></script>
<script src="http://www.amcharts.com/lib/3/serial.js"></script>
<div id="chartdiv" style="width: 100%; height: 362px;"></div>

JavaScript

var chart;

var chartData = [{
    "series": "1",
    "value": 1114,
    "color": "#0D52D1"
}, {
    "series": "2",
    "value": 984,
    "color": "#CD0D74"
}, {
    "series": "3",
    "value": 711,
    "color": "#CD0D74"
}, {
    "series": "4",
    "value": 665,
    "color": "#0D52D1"
}, {
    "series": "5",
    "value": 580,
    "color": "#CD0D74"
}, {
    "series": "6",
    "value": 443,
    "color": "#CD0D74"
}, {
    "series": "7",
    "value": 441,
    "color": "#CD0D74"
}];


AmCharts.ready(function () {
    // SERIAL CHART
    chart = new AmCharts.AmSerialChart();
    chart.dataProvider = chartData;
    chart.categoryField = "series";
    chart.startDuration = 0;
    
    // AXES
    // category
    var categoryAxis = chart.categoryAxis;
    categoryAxis.gridAlpha = 0;
    categoryAxis.fillAlpha = 1;
    categoryAxis.fillColor = "#FAFAFA";
    categoryAxis.gridPosition = "start";
    
    // regular value axis
    var valueAxis = new AmCharts.ValueAxis();
    chart.addValueAxis(valueAxis);
    
    // value axis used for fills
    var valueAxisColumn = new AmCharts.ValueAxis();
    valueAxisColumn.axisAlpha = 0;
    valueAxisColumn.stackType = "100%";
    valueAxisColumn.labelsEnabled = false;
    valueAxisColumn.gridAlpha = 0;
    valueAxisColumn.axisAlpha = 0;
    chart.addValueAxis(valueAxisColumn);
    
    // Collumns
    var graph = new AmCharts.AmGraph();
    graph.valueAxis = valueAxisColumn;
    graph.valueField = "value";
    graph.colorField = "color";
    graph.type = "column";
    graph.columnWidth = 1.01;
    graph.lineAlpha = 0;
    graph.fillAlphas = 1;
    graph.showBalloon = false;
    chart.addGraph(graph);
    
    // regular graph
    graph = new AmCharts.AmGraph();
    graph.valueField = "value";
    graph.lineThickness = 2;
    graph.bullet = "round";
    chart.addGraph(graph);
    
    // CURSOR
    var chartCursor = new AmCharts.ChartCursor();
    chartCursor.cursorAlpha = 0;
    chartCursor.zoomable = false;
   ...