This sample is to set the colors of Radar Chart.

backgroundElements: Defines the background style of the chart. GridLines is the default method.
radialAxisRenderers: Defines the renderer for radialAxis.
	e.g.) sets the color, location and text style of the axis
RadarSeries: sets the line style of the radar. sets the fill color of the radar, etc.

Please refer to the source code of Layout and HTML for the details.