series.legendItem.area.backgroundString

The background color of the legend item. Accepts a valid CSS color string, including HEX and RGB. Defaults to the series color.

Example - set the area legend item background

<div id="chart"></div>
<script>
$("#chart").kendoChart({
  series: [{
    type: "area",
    name: "Series A",
    data: [1, 2, 3],
    legendItem: {
      area: {
        background: "red"
      }
    }
  }]
});
</script>