Hichart Export PNG不显示颜色

Question

我创建了一个散点图，当我尝试下载时，颜色全为黑色。

我尝试更改Highchart版本，但也无法正常工作。

这是jsfiddle示例，要下载图表，请单击右上角的蓝色按钮。

http://jsfiddle.net/danilotorabit/kg20Ljey/3/

在jsfiddle上完整的Js文件

Highcharts.chart('container',{  
   "chart": {
      "zoomType": "xy", "type": "scatter"
   }, 
   "exporting": {
      "buttons": {
         "contextButton": {"enabled": false}, 
         "exportButton": {
            "_titleKey": "export_buttonTitle", 
            "symbol": "url(http://torabit.com.br/img/icone_download.png)", 
            "onclick": function () { this.exportChart() }}}, 
            "filename": "gr_scatter"
   },
   "plotOptions": {
      "scatter": {
         "marker": {
            "states": {
               "hover": {
                  "enable": "true", 
                  "lineColor": "rgb(100,100,100)"}
                  }, 
            "radius": 5
         }, 
      }
   }, 
   "series": [{"marker": {"symbol": "circle"}, "color": "rgba(219,68,55)", "data": [[120, 5.06], [230, 10.25], [340, 3.02], [450, 7.44]], "name": "Ana Luiza Amaral"},  
              {"marker": {"symbol": "circle"}, "color": "rgba(193,187,61)", "data": [[105, 10.04], [545, 3.3]], "name": "Vinicius Rossignoli"}],
   "title": {
      "text": "Assuntos por tipos"
   },  
   "xAxis": {
      "min": "0", 
      "max": "550", 
      "plotBands": [{"to": 115, "from": 0, "label": {"text": "Aleat\u00f3rio", "aling": "center"}}, 
                    {"color": "rgba(245,245,245)", "to": 225, "from": 110, "label": {"text": "Cr\u00edtica", "aling": "center"}}, 
                    {"to": 335, "from": 220, "label": {"text": "Piada", "aling": "center"}}, 
                    {"color": "rgba(245,245,245)", "to": 445, "from": 330, "label": {"text": "Propaganda", "aling": "center"}}, 
                    {"to": 555, "from": 440, "label": {"text": "Torcida", "aling": "center"}}], 
      "labels": {
         "style": {
            "color": "white"
         }
      }, 
      "startOnTick": "false", 
      "endOnTick": "false", 
      "tickColor": "#FFFFF", 
      "title": {"enable": "false"}
   },
   "yAxis": {
      "title": {
         "text": "Porcentagem (%)"
      }
   },   
});