Change color of beamer icon

src/app/components/shared/comment/comment.component.html

@@ -11,7 +11,7 @@
         </ng-template>
       </div>
       <button mat-icon-button *ngIf="comment.read" [disabled]="true" (click)="setRead(comment)">
-        <mat-icon svgIcon="beamer" [ngClass]="{'read-icon': comment.read, 'not-marked' : !comment.read}"
+        <mat-icon svgIcon="beamer" class="not-marked">
                   matTooltip="{{ 'comment-page.mark-read' | translate }}">
         </mat-icon>
       </button>