如何仅使用箭头键切换背景颜色的更改？

<div id="myElement" style="background-color: red;"></div>

document.addEventListener("keydown", function(event) {
  var element = document.getElementById("myElement");
  var currentColor = element.style.backgroundColor;

  if (event.key === "ArrowUp") {
    // 向上箭头键，切换为红色背景
    element.style.backgroundColor = "red";
  } else if (event.key === "ArrowDown") {
    // 向下箭头键，切换为蓝色背景
    element.style.backgroundColor = "blue";
  } else if (event.key === "ArrowLeft") {
    // 向左箭头键，切换为绿色背景
    element.style.backgroundColor = "green";
  } else if (event.key === "ArrowRight") {
    // 向右箭头键，切换为黄色背景
    element.style.backgroundColor = "yellow";
  }

  // 输出当前背景颜色
  console.log("当前背景颜色：" + element.style.backgroundColor);
});