Ionic 3弹出窗口颜色变化

Question

我需要更改警报弹出窗口的css，这意味着我想将标题颜色更改为白色，将背景颜色更改为灰色。有人可以帮忙吗？谢谢。

 presentPrompt() {
  let alert = this.alertCtrl.create({
    title: 'Add Your Question',
    inputs: [
      {
        name: 'would',
        placeholder: 'Would You ',
      },
      {
        name: 'rather',
        placeholder: 'Rather'
      }
    ],
    buttons: [
      {
        text: 'Add',
        role: 'add',
        handler: data => {
          this.wouldquestion = data.would;
          this.ratherquestion = data.rather;
          this.afd.list("Questions/").push({
            would:this.wouldquestion,
            rather:this.ratherquestion,
            ratherclick:this.ratherclicks,
            wouldclick:this.wouldclicks
          });
        }
      },
          ]
  });
  alert.present();
}

Answer 1

<form>
  <input type="text" class="regFname" placeholder="First name: ">
  <button type="button">Register</button>
</form>
<p>Current Users</p>
<ul></ul>