Change checkbox color to primary

src/app/participant-choice-content/participant-choice-content.component.html

@@ -14,7 +14,7 @@
       <mat-divider></mat-divider>
       <mat-card-content>
         <mat-list *ngFor="let answer of testChoiceContent.options">
-          <mat-checkbox>{{answer.label}}</mat-checkbox>
+          <mat-checkbox color="primary">{{answer.label}}</mat-checkbox>
         </mat-list>
       </mat-card-content>
     </mat-card>