By default, the Contrast on all channels is 50%, which indicates that no effect is applied to the layer. The Contrast property specifies the percent of contrast to apply to the layer. Use the DefaultLayer(exDefLayerContrast...) property to specify the default value for the Contrast(exAllChannels...), before adding any layer. The Brightness / Contrast properties can be used to change the percent of specified color to be applied on the layer. You can use the Grayscale property to show the entire layer in gray scale ( disable state).

The following screen shot shows the layer, with all Contrast properties on 50% ( default ):

The following screen shot shows the layer, with more red, Contrast(exAllChannels) = 0, Contrast(exRedChannel) = 75:

By default, the AllowSmoothChange property is exLayerTransparency | exLayerBrightness | exLayerContrast. Use the AllowSmoothChange property to disable changing gradually any brightness / contrast or the transparency, of the layer. For instance, a gradually change means that you can change the layer's transparency from 0 to 50 in a short time, with intermediate values ( smooth change ). 

The AllowSmoothChange property changes gradually one / or more properties like follow:

• Brightness,  Specifies the percent of brightness to apply to the layer.
• Contrast,  Specifies the percent of contrast to apply to the layer.
• Transparency,  Gets or sets a value that indicates percent of the transparency to display the layer.

The MouseIn / MouseOut event notifies your application when the cursor is entering / leaving the layer. The MouseMove event is generated continually as the mouse pointer moves across objects. The AllowSmoothChange property specifies the properties of the layers that support smooth change. For instance, you can use the MouseIn / MouseOut event to change gradually the brightness / contrast or the transparency, of the layer, while the AllowSmoothChange property is not exSmoothChangeless.