color blur in echart

1var columnProto = Highcharts.seriesTypes.column.prototype;
2
3columnProto.axisTypes = ['xAxis', 'yAxis', 'colorAxis'];
4columnProto.optionalAxis = 'colorAxis';
5columnProto.colorKey = 'y';
6
7Highcharts.wrap(columnProto, 'translate', function(proceed) {
8    proceed.apply(this, Array.prototype.slice.call(arguments, 1));
9
10    Highcharts.seriesTypes.heatmap.prototype.translateColors.call(this);
11});
12
13Highcharts.chart('container', {
14    series: [{
15        type: 'bar',
16        data: [1, 2, 3, 4, 5, 6, 7, 8, 9]
17    }],
18    colorAxis: {
19        minColor: '#c6e48b',
20        maxColor: '#196127',
21        min: 1,
22        max: 9
23    }
24});
25