StartCap

<div id="diagram"></div>
<script>
  $("#diagram").kendoDiagram({
    shapes: [{
      visual: function() {
        var group = new kendo.dataviz.diagram.Group();
        group.append(new kendo.dataviz.diagram.Path({
          data: 'M 0,0 L100,100',
          startCap: {
            type: "ArrowStart",
            fill: "red"
          }
        }));
        return group;
      }
    }]
  });
</script>

<div id="diagram"></div>
<script>
  $("#diagram").kendoDiagram({
    shapes: [{
      visual: function() {
        var group = new kendo.dataviz.diagram.Group();
        group.append(new kendo.dataviz.diagram.Path({
          data: 'M 0,0 L100,100',
          startCap: {
            type: "ArrowStart",
            fill: {
              color: "green",
              opacity: 0.9
            }
          }
        }));
        return group;
      }
    }]
  });
</script>

<div id="diagram"></div>
<script>
  $("#diagram").kendoDiagram({
    shapes: [{
      visual: function() {
        var group = new kendo.dataviz.diagram.Group();
        group.append(new kendo.dataviz.diagram.Path({
          data: 'M 0,0 L100,100',
          startCap: {
            type: "ArrowStart",
            fill: "red",
            stroke: {
              color: "black",
              width: 2
            }
          }
        }));
        return group;
      }
    }]
  });
</script>

<div id="diagram"></div>
<script>
  $("#diagram").kendoDiagram({
    shapes: [{
      visual: function() {
        var group = new kendo.dataviz.diagram.Group();
        group.append(new kendo.dataviz.diagram.Path({
          data: 'M 0,0 L100,100',
          startCap: {
            type: "FilledCircle",
            fill: "purple"
          }
        }));
        return group;
      }
    }]
  });
</script>