百度echarts如何对不同折线图设置不同颜色

series: [
  {
    name: '折线图1',
    type: 'line',
    data: [111, 222, 333, 444, 111, 222, 333, 444, 111],
    itemStyle: {
      normal: {
        color: '#15CE89',
        lineStyle: {
          color: '#15CE89'
        }
      }
    },
    showSymbol: true,
    smooth: 0.6, //拐点圆形
    symbol: 'circle', //形状 'circle’, 'rect’, 'roundRect’, 'triangle’, 'diamond’, 'pin’, 'arrow'
    symbolSize: 0 //大小
  },
  {
    name: '折线图2',
    type: 'line',
    data: [222, 333, 444, 111, 222, 333, 444, 111, 222],
    itemStyle: {
      normal: {
        color: '#FFBB00',
        lineStyle: {
          color: '#FFBB00'
        }
      }
    }
  },
  {
    name: '折线图3',
    type: 'line',
    data: [333, 444, 111, 222, 333, 444, 111, 222, 333],
    itemStyle: {
      normal: {
        color: '#0075FF',
        lineStyle: {
          color: '#0075FF'
        }
      }
    }
  },
  {
    name: '折线图4',
    type: 'line',
    data: [444, 111, 222, 333, 444, 111, 222, 333, 444],
    itemStyle: {
      normal: {
        color: '#FF844D',
        lineStyle: {
          color: '#FF844D'
        }
      }
    }
  }
]