How to customise the error message color

Ionic Framework ionic-v3
1

I have a code as below, and I would like to customize the error message color if the input is empty, but I have no idea how to do it.
Can anybody advise?

  <form [ngFormModel]="loginForm">
    <ion-input type="email" placeholder="Email" ngControl="email">
    </ion-input>
    <div *ngIf="loginForm.controls.email.hasError('required') && loginForm.controls.email.touched">* Email is required!</div>
2

Just add a class to your error div, like class=“alertmsg”, then in your style.css add a class:

.alertmsg {
  color: red;
}
3

Does Ionic 2 still using style.css? I just saw app.variables.scss or <page_name>.scss.