If you want a property on your gauge to be one solid color, set the brush type to Solid. When you select the Solid brush element, you can select from a number of available colors. You can apply the Solid brush element to the properties on your gauge using:
The following screen shot displays a Radial gauge with the Dial’s BrushElement property set to a SolidFillBrushElement with the following setting:
Solid color — Black