数据中添加itemStyle,修改颜色为渐变色

option = {
  tooltip: {
    show:false,
    trigger: 'item'
  },
  legend: {
    top: '5%',
    left: 'center'
  },
  series: [
    {
      name: 'Access From',
      type: 'pie',
      radius: ['40%', '70%'],
      avoidLabelOverlap: false,
      
      label: {
        show: false,
        position: 'center',
        color: 'red'
      },
      emphasis: {
        label: {
          show: true,
          fontSize: 40,
          fontWeight: 'bold',
          formatter(data){
    
            return '111'
          },
          color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [{
            offset: 0,
            color: 'blue'
        }, {
            offset: 1,
            color: 'red'
        }])
        }
      },
      labelLine: {
        show: false
      },
      data: [
        { value: 1048, name: 'Search Engine',itemStyle: {
            color: new echarts.graphic.LinearGradient( 0, 1, 1, 1,
                [
                    {offset: 0, color: 'rgba(23, 75, 224, 0.5)'},
                    {offset: 1, color: 'rgba(23, 75, 224, 1)'}, 
                ]
            )
          },
 },
        { value: 735, name: 'Direct',itemStyle: {
            color: new echarts.graphic.LinearGradient( 0, 1, 1, 1,
                [
                    {offset: 0, color: 'rgba(0, 215, 223, 0.5)'},
                    {offset: 1, color: 'rgba(0, 215, 223, 1)'}, 
                ]
            )
          }, },
        { value: 580, name: 'Email',itemStyle: {
            color: new echarts.graphic.LinearGradient( 0, 1, 1, 1,
                [
                    {offset: 0, color: 'rgba(36, 182, 255, 0.5)'},
                    {offset: 1, color: 'rgba(36, 182, 255, 1)'}, 
                ]
            )
          }, },
        { value: 484, name: 'Union Ads',itemStyle: {
            color: new echarts.graphic.LinearGradient( 0, 1, 1, 1,
                [
                    {offset: 0, color: 'rgba(221, 175, 96, 0.5)'},
                    {offset: 1, color: 'rgba(221, 175, 96, 1)'}, 
                ]
            )
          }, },
        { value: 300, name: 'Video Ads',itemStyle: {
            color: new echarts.graphic.LinearGradient( 0, 1, 1, 1,
                [
                    {offset: 0, color: 'rgba(18, 191, 111, 0.5)'},
                    {offset: 1, color: 'rgba(18, 191, 111, 1)'}, 
                ]
            )
          }, }
      ]
    }
  ]
};