如何在MVVM中设置Area图表的边框颜色？

Question

如何在MVVM中设置区域图的边框颜色？

<div data-role="chart"
 data-legend="{ position: 'bottom' }"
 data-series-defaults="{ type: 'area' }"
 data-series-colors="['#A2A2A2']"

 data-series="[
                 { field: 'id', name: 'id' , labels: {visible: true},line: {style:'smooth'}}
             ]"

 data-bind="source: sourceId,
            events: { seriesHover: onSeriesHoverIndex }"
 style="height: 250px;" >

像这个附加图像的东西