Radial
Parameters
inner Radius
how much of the shape should be filled entirely with color1
outer Radius
how much of the shape should be filled entirely with color2
center X
the center of the gradient, in the x-axis. if it is -1, it will be the center of the shape
center Y
the center of the gradient, in the y-axis. if it is -1, it will be the center of the shape