我无法在Chart.js中更改网格的颜色

var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
    type: 'line',
    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)',
            borderColor: 'rgba(255, 99, 132, 1)',
            borderWidth: 1
        }]
    },
    options: {
        scales: {
            xAxes: [{
                gridLines: {
                    color: 'rgba(0, 0, 0, 0.2)' // 修改 x 轴的网格颜色
                }
            }],
            yAxes: [{
                gridLines: {
                    color: 'rgba(0, 0, 0, 0.2)' // 修改 y 轴的网格颜色
                }
            }]
        }
    }
});