If you want a property of your gauge to start with one color and fade into another color in a specific way, apply the Simple Gradient brush element to the property.
To apply a Simple Gradient brush element to a property of your gauge at design time:
Add a Radial Gauge to the Gauges collection.
In the left-hand pane of the Gauges collection editor, click Radial Gauge.
Expand the Dial property.
From the BrushElement drop-down list, select Simple Gradient. This will create a new Simple Gradient brush element.
Expand the newly created BrushElement property, and set the following properties:
StartColor - Click the drop-down arrow. The color picker appears. On the top, click Web, then select the Firebrick color.
End Color - Click the drop-down arrow. The color picker appears. On the top, click Web, then select the Black color.
Gradient Style - From the drop-down list, select Backward Diagonal.