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