An object specifying the default properties for RadialGradients using in fills patterns.
An array of colors at given offsets (from the center of the radial gradient). The center is defined at offest 0 with the outer edge of the gradient at offset 1. Default value, [{ offset: 0, color: 'black'},{offset: 1, color: 'white'}], is a gradient from black to white.
The X coordinate of the center of the radial gradient, default value 0.
The Y coordinate of the center of the radial gradient, default value 0.