how to add gradient for the sections in pie chart

[pranitakale]

Getting undefined for the Highcharts.Color colors: { radialGradient: {cx: 0.5, cy: 0.3, r: 0.7}, stops: [ [0, globals.legendColor], [1, Highcharts.Color(globals.legendColor).brighten(-0.3).get('rgb')] ] }