Chart.js填充不适用于ScaleLabel

var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: ['Red', 'Blue', 'Yellow', 'Green', 'Purple', 'Orange'],
        datasets: [{
            label: '# of Votes',
            data: [12, 19, 3, 5, 2, 3],
            backgroundColor: [
                'rgba(255, 99, 132, 0.2)',
                'rgba(54, 162, 235, 0.2)',
                'rgba(255, 206, 86, 0.2)',
                'rgba(75, 192, 192, 0.2)',
                'rgba(153, 102, 255, 0.2)',
                'rgba(255, 159, 64, 0.2)'
            ],
            borderColor: [
                'rgba(255, 99, 132, 1)',
                'rgba(54, 162, 235, 1)',
                'rgba(255, 206, 86, 1)',
                'rgba(75, 192, 192, 1)',
                'rgba(153, 102, 255, 1)',
                'rgba(255, 159, 64, 1)'
            ],
            borderWidth: 1
        }]
    },
    options: {
        scales: {
            yAxes: [{
                scaleLabel: {
                    display: true,
                    labelString: 'Value',
                    fontColor: 'black',
                    fontSize: 14,
                    fontStyle: 'bold',
                    padding: {
                        top: 10,
                        bottom: 10
                    },
                    backgroundColor: 'rgba(255, 255, 255, 0.8)' // 这里设置填充颜色
                }
            }],
            xAxes: [{
                scaleLabel: {
                    display: true,
                    labelString: 'Category',
                    fontColor: 'black',
                    fontSize: 14,
                    fontStyle: 'bold',
                    padding: {
                        left: 10,
                        right: 10
                    },
                    backgroundColor: 'rgba(255, 255, 255, 0.8)' // 这里设置填充颜色
                }
            }]
        }
    }
});

Chart.plugins.register({
    afterDraw: function(chartInstance) {
        if (chartInstance.config.options.scales.yAxes[0].scaleLabel && chartInstance.config.options.scales.yAxes[0].scaleLabel.backgroundColor) {
            var ctx = chartInstance.chart.ctx;
            var scaleLabel = chartInstance.config.options.scales.yAxes[0].scaleLabel;
            var x = chartInstance.scales['y-axis-0'].xScale.left;
            var y = chartInstance.scales['y-axis-0'].yScale.top - 20; // 调整位置
            var width = chartInstance.scales['y-axis-0'].width;
            var height = 20; // 调整高度

            ctx.save();
            ctx.fillStyle = scaleLabel.backgroundColor;
            ctx.fillRect(x, y, width, height);
            ctx.restore();
        }
    }
});

var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        // 数据配置
    },
    options: {
        scales: {
            yAxes: [{
                scaleLabel: {
                    display: true,
                    labelString: 'Value',
                    backgroundColor: 'rgba(255, 255, 255, 0.8)'
                }
            }]
        }
    },
    plugins: {
        customPlugin: true
    }
});