scale.labels.border.colorString
The color of the border. Any valid CSS color string will work here, including hex and rgb.
Example
<div id="gauge"></div>
<script>
$("#gauge").kendoArcGauge({
value: 65,
scale: {
labels: {
border: {
color: "#ff6800",
width: 1
}
}
}
});
</script>