获取div，改变颜色

for(){
div.onclick=function(){
if(){
怎样点击变色 取消变色
}
}
}

改变背景颜色用
box.style.backgroundColor
改变字体颜色
box.style.color

// div-test为元素id
document.getElementById('div-test').style.color = "red"
document.getElementById('div-test').style.backgroundColor = "red"


<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      #box {
        width: 200px;
        height: 200px;
        background-color: black;
      }
    </style>
  </head>
  <body>
    <div id="box" onclick="boxClick()"></div>
    <script>
      let box = document.getElementById("box");
      function boxClick() {
        if (box.style.backgroundColor === "red") {
          box.style.backgroundColor = "black";
        } else {
          box.style.backgroundColor = "red";
        }
      }
    </script>
  </body>
</html>