amcharts4 - 如何使 CategoryAxis 背景不透明度 = 1

Question

我在 RadarChart 上有一个 CategoryAxis，我想让背景变成不透明度 = 0.5 的浅灰色。

我该怎么做？

var categoryAxis = chart.yAxes.push(new am4charts.CategoryAxis());
categoryAxis.dataFields.category = "category";
categoryAxis.renderer.labels.template.fontSize = 15;
categoryAxis.renderer.labels.template.fontWeight = "bold";
categoryAxis.renderer.labels.template.horizontalCenter = "right";
categoryAxis.renderer.grid.template.location = 0;
categoryAxis.renderer.grid.template.strokeOpacity = 0.5;
categoryAxis.renderer.grid.template.opacity = 0.5;
categoryAxis.renderer.axisFills.template.disabled = true;
categoryAxis.mouseEnabled = false;