All gauge elements, except text labels and images, have the following properties in the Appearance category: Border (C1GaugeBorder), Filling (C1GaugeFilling), Gradient (C1GaugeGradient).

Border specifies the color, thickness, and style of the pen that draws the element border. The default border color is the same as ForeColor of the owner C1Gauge control. To hide the border set its C1GaugeBorder.LineStyle property to None. To display a semitransparent border specify the value of alpha when setting the C1GaugeBorder.Color property, for example: "128, 0, 0, 0".

The Filling property specifies how to draw the interior. BrushType is the main property of the C1GaugeFilling class. The filling color is defined by a pair of properties: Color and Opacity. Some brushes use the second pair of color properties as well: Color2, Opacity2. You may switch these pairs using the SwapColors property. The following are possible values for the BrushType property:

• None – the element has no filling.
• SolidColor – the element is filled with a single color specified by the Color property. If this property is empty, the BackColor property of the owner C1Gauge control is used instead.
• Hatch – fills the element with one of the predefined hatch styles (selected by the HatchStyle property) using a foreground color (Color) and a background color (Color2).
• Texture – fills the interior of an element using an image provided in the C1GaugeFilling.TextureImage property. The wrap mode for the texture brush is specified by the C1GaugeFilling.WrapMode property.
• Gradient – the interior is filled with a gradient that is defined by the Gradient property (see below).

The Gradient property provides a few settings for drawing a gradient. The C1GaugeGradient.Direction property sets the direction of the gradient orientation line, such as Vertical, Radial, and so on. The RadialInner value draws the gradient that is inscribed into the owner element. The RadialOuter value draws the circumscribed gradient. The C1GaugeGradient.Falloff property allows using the bell-shaped or triangular gradient effects. The C1GaugeGradient.TranslateX and C1GaugeGradient.TranslateY properties allow moving the area filled with the gradient by the specified relative amount, and then the C1GaugeGradient.ScaleX and C1GaugeGradient.ScaleY properties scale this area, if necessary.

If several elements have similar borders, fillings, or gradients you can create the common templates that can be shared between several objects. Both C1Gauge and C1GaugeBase classes have the special collections of common items: CommonBorders, CommonFillings, and CommonGradients. Each common item, such as a CommonBorder and CommonFilling, has the Name property. If this property is not empty you can choose the specified name from the drop-down list that opens for the Border, Filling, and Gradient properties of various gauge elements. To reference a common item from code, you should assign the item name to the following properties: C1GaugeBorder.CommonBorderName, C1GaugeFilling.CommonFillingName, C1GaugeGradient.CommonGradientName.