Changing border color in mat-form-field

Question

I am using angular material mat-form-field. I have a dark background, and therefore am trying to change the border of the form-field to white. But I am not able

Answer 1

For the newer outlined form fields, solved it this way:

::ng-deep {
     .mat-form-field-appearance-outline .mat-form-field-outline {
        color: white;
     }
     mat-form-field {
        .mat-hint, input, ::placeholder, .mat-form-field-label {
           color: white;
        }
     }
  }