如何让折线图在某个范围内是绿色，范围外是红色呢echarts 折线配置项内容和展示

如何让折线图在某个范围内是绿色，范围外是红色呢

      option = {
    title: {
        text: 'Awesome Chart'
    },
    xAxis: {
        data: ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat']
    },
    yAxis: {},
    series: [{
            type: 'line',
            data: [250, 182, 80, 234, 290, 330, 310]
        },
        {
            name: '下限',
            type: 'line',
            data: [115],
            markLine: {
                data: [{
                    type: 'average',
                    name: '平均值'
                }]
            }
        },
        {
            name: '上限',
            type: 'line',
            data: [215],
            markLine: {
                data: [{
                    type: 'average',
                    name: '平均值'
                }]
            }
        }
    ],
    visualMap: {
        pieces: [{
            gt: 0,
            lte: 115,
            color: '#f00'
        }, {
            gt: 115,
            lte: 215,
            color: '#0f0'
        }, {
            gt: 215,
            lte: 350,
            color: '#00f'
        }]
    }
};