echart中如何实现使用自定义单个柱状颜色（附代码）

option = {
    title: {
        text: 'ECharts 示例'
    },
    tooltip: {},
    legend: {
        data:['销量']
    },
    xAxis: {
        data: ["衬衫","羊毛衫","雪纺衫","裤子","高跟鞋","袜子"],
        axisLabel: {color: 'green'}
    },
    yAxis: {},
    series: [{
        name: '销量',
        type: 'bar',
        data: [5, 20, 36, 10, 10, 20],
        itemStyle: {
            color: function(params){
                var c ='';
                if(params.value>20){
                    c='red'
                }else{
                    c='green'
                }
                return c;
            }
        }
    }]
};

option = {
    title: {
        text: 'ECharts 示例'
    },
    tooltip: {},
    legend: {
        data:['销量']
    },
    xAxis: {
        data: ["衬衫","羊毛衫","雪纺衫","裤子","高跟鞋","袜子"],
        axisLabel: {color: 'green'}
    },
    yAxis: {},
    series: [{
        name: '销量',
        type: 'bar',
        data: [5, 20, {
            value:'35',
            itemStyle: {
                color: 'orange'
            }
        }, 10, 10, 20]
    }]
};