删除新表单行中的背景色

<form id="myForm">
  <table>
    <thead>
      <tr>
        <th>列1</th>
        <th>列2</th>
        <th>列3</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td><input type="text" name="col1"></td>
        <td><input type="text" name="col2"></td>
        <td><input type="text" name="col3"></td>
      </tr>
    </tbody>
  </table>
  <button onclick="addRow()">新增行</button>
</form>

tr.new-row {
  background-color: #ffffff; /* 默认背景色 */
}

function addRow() {
  var table = document.querySelector("#myForm table");
  var newRow = table.insertRow(-1);
  newRow.className = "new-row"; // 设置新行的类名
  var cell1 = newRow.insertCell(0);
  var cell2 = newRow.insertCell(1);
  var cell3 = newRow.insertCell(2);
  cell1.innerHTML = '<input type="text" name="col1">';
  cell2.innerHTML = '<input type="text" name="col2">';
  cell3.innerHTML = '<input type="text" name="col3">';
}

function deleteRow(row) {
  var table = document.querySelector("#myForm table");
  table.deleteRow(row.rowIndex);
}

<button onclick="deleteRow(this.parentNode.parentNode)">删除行</button>