Answered by : horrible-hare-lxw6g8mbc1w2

.container { .mat-form-field-outline, .mat-form-field-empty.mat-form-field-label, .mat-form-field-label, .mat-form-field-underline, .mat-input-element, ::placeholder { color: $white !important; }
}

Source : https://stackoverflow.com/questions/41205931/how-do-i-change-md-input-container-placeholder-color-using-css-in-angular-materi | Last Update : Wed, 17 Feb 21