The C1GaugeDecorator.Frcontrol includes a pointer which indicates the selected C1Gauge.Value of the control. The pointer consists of the C1GaugePointer element:

The C1GaugePointer element appears by default as a brown tapering element, but you can customize the appearance of the C1GaugePointer element by setting several properties, including the C1Gauge.PointerFill, C1Gauge.PointerLength, C1Gauge.PointerOffset, C1Gauge.PointerStroke, C1Gauge.PointerStrokeThickness, C1Gauge.PointerStyle, C1Gauge.PointerVisibility, and C1Gauge.PointerWidth properties. You can also customize how the C1GaugePointer element appears by setting the C1LinearGaugePointer.Orientation property to Vertical or Horizontal.