seriesDefaults.focusHighlight.border.opacity Number (default: 1)

The opacity of the focus highlight border.

Example - set the chart seriesDefaults focus highlight border opacity

<div id="chart"></div>
<script>
$("#chart").kendoChart({
  seriesDefaults: {
    focusHighlight: {
      border: {
        opacity: 0.5
      }
    }
  },
  series: [
    { type: "donut",  data: [3, 4] }
  ]
});
</script>