如何在Google图表库中的刻度区域网格中显示颜色

google.charts.load('current', {packages: ['corechart']});
google.charts.setOnLoadCallback(drawChart);

function drawChart() {
  var data = google.visualization.arrayToDataTable([
    ['Year', 'Sales', 'Expenses'],
    ['2016', 1000, 400],
    ['2017', 1170, 460],
    ['2018', 660, 1120],
    ['2019', 1030, 540]
  ]);

  var options = {
    vAxis: {
      gridlines: {
        color: 'red', // 设置刻度区域网格的颜色为红色
        count: 5 // 设置刻度区域网格的数量为5
      }
    }
  };

  var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
  chart.draw(data, options);
}