Creates a gradient brush that changes color starting from the center of the path outward to the path's boundary. The transition from one color to another is based on a bell-shaped curve.
If there is more than one color in the PathGradientBrush.SurroundColors array, the first color in the array is used for the ending color. The colors specified in this array are colors used for discrete points on the brush's boundary path.
By default, as you move from the boundary of a path gradient to the center point, the color changes gradually from the boundary color to the center color. You can customize the positioning and blending of the boundary and center colors by calling this method.