This .NET class wraps the AcGiGradientBackgroundTraits ObjectARX class. 

GradientBackgroundTraits represents a gradient background to the underlying display system. An instance of this class is populated by GradientBackground through its SetAttributes method. 

Autodesk.AutoCAD.GraphicsInterface.SubEntityTraits
    Autodesk.AutoCAD.GraphicsInterface.DrawableTraits
        Autodesk.AutoCAD.GraphicsInterface.NonEntityTraits
            Autodesk.AutoCAD.GraphicsInterface.GradientBackgroundTraits

Public abstract Class GradientBackgroundTraits
Inherits NonEntityTraits

public abstract class GradientBackgroundTraits : NonEntityTraits;