Echarts分段折线图图例样式visualMap颜色修改_js
textStyle: { //图例文字的样式
                            color: '#fff',
                            fontSize: 16
},
<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
        <script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
        <script src="https://cdn.bootcss.com/echarts/4.2.1-rc1/echarts.min.js" type="text/javascript"></script>
    </head>
    <body>
        <!-- 为ECharts准备一个具备大小(宽高)的Dom -->
        <div id="main" class="col-md-12  col-sm-12 col-xs-12" style="height: 400px;"></div>
        <script>
            // 折线图
            $.ajax({
                url: "test.json",
                data: {},
                type: 'GET',
                success: function(data) {
                    console.log(JSON.stringify(data))
                    hrFun(data.echatX, data.echatY);
                },
            });


            var myChart = echarts.init(document.getElementById("main"));

            function hrFun(x_data, y_data) {
                myChart.setOption(option = {
                    title: {
                        text: 'Beijing AQI'
                    },
                    tooltip: {
                        trigger: 'axis'
                    },
                    xAxis: {
                        data: x_data
                    },
                    yAxis: {
                        splitLine: {
                            show: false
                        }
                    },
                    toolbox: {
                        left: 'center',
                        feature: {
                            dataZoom: {
                                yAxisIndex: 'none'
                            },
                            restore: {},
                            saveAsImage: {}
                        }
                    },
                    dataZoom: [{
                        startValue: '2014-06-01'
                    }, {
                        type: 'inside'
                    }],
                    visualMap: {
                        top: 10,
                        right: 10,
                        textStyle: { //图例文字的样式
                            color: '#fff',
                            fontSize: 16
                        },
                        pieces: [{
                            gt: 0,
                            lte: 1,
                            label: '活动',
                            color: '#096'
                        }, {
                            gt: 1,
                            lte: 2,
                            label: '浅睡',
                            color: '#ffde33'
                        }, {
                            gt: 2,
                            lte: 3,
                            label: '深睡',
                            color: '#ff9933'
                        }, {
                            gt: 3,
                            lte: 4,
                            label: '熟睡',
                            color: '#cc0033'
                        }],
                        outOfRange: {
                            color: '#999'
                        }
                    },
                    series: {
                        name: '睡眠状态',
                        type: 'line',
                        data: y_data,
                        //虚线
                        // markLine: {
                        //     silent: true,
                        //     data: [{
                        //         yAxis: 1
                        //     }, {
                        //         yAxis: 2
                        //     }, {
                        //         yAxis: 3
                        //     }, {
                        //         yAxis: 4
                        //     }]
                        // }
                    }
                });
            }
        </script>
    </body>
</html>

json数据
格式是数组对象的时候

{
    "echatX": ["2020-11-17 14:47:18", "2020-11-17 14:49:44", "2020-11-17 14:52:11", "2020-11-17 14:54:36",
        "2020-11-17 14:57:01", "2020-11-17 14:59:28", "2020-11-17 15:01:55", "2020-11-17 15:04:23", "2020-11-17 15:06:51",
        "2020-11-17 15:09:20", "2020-11-17 15:11:44", "2020-11-17 15:14:10", "2020-11-17 15:16:38", "2020-11-17 15:19:01",
        "2020-11-17 15:21:26", "2020-11-17 15:23:53", "2020-11-17 15:26:20", "2020-11-17 15:28:47", "2020-11-17 15:31:14",
        "2020-11-17 15:33:41", "2020-11-17 15:36:09", "2020-11-17 15:38:38", "2020-11-17 15:41:07", "2020-11-17 15:43:35",
        "2020-11-17 15:46:01", "2020-11-17 15:48:25", "2020-11-17 15:50:52", "2020-11-17 15:53:20", "2020-11-17 15:55:55",
        "2020-11-17 15:58:35", "2020-11-17 16:01:04", "2020-11-17 16:01:19", "2020-11-17 16:03:49", "2020-11-17 16:04:05",
        "2020-11-17 16:06:34", "2020-11-17 16:06:50", "2020-11-17 16:09:17", "2020-11-17 16:09:32", "2020-11-17 16:11:56",
        "2020-11-17 16:12:13", "2020-11-17 16:14:38", "2020-11-17 16:14:54", "2020-11-17 16:17:20", "2020-11-17 16:17:37",
        "2020-11-17 16:20:02", "2020-11-17 16:20:18", "2020-11-17 16:22:51", "2020-11-17 16:23:10", "2020-11-17 16:25:43",
        "2020-11-17 16:26:00", "2020-11-17 16:28:26", "2020-11-17 16:28:43", "2020-11-17 16:31:07", "2020-11-17 16:31:24",
        "2020-11-17 16:33:58", "2020-11-17 16:34:17"
    ],
    "echatY": [1, 1, 1, 1, 1, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
        3, 2, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 3, 3, 4, 4, 4, 4
    ],
    "echatY2": null
}
Echarts分段折线图图例样式visualMap颜色修改_javascript_02