Change icon in check box

HTML

<ion-item>
                <ion-label>Daenerys Targaryen</ion-label>
                <ion-checkbox color="dark" checked="true"></ion-checkbox>
            </ion-item>

scss

   .checkbox-icon {
                border-color: #999 !important;
                background-color: #fff!important;
            }
            .checkbox-checked {
                background-color: #a71818!important;
                border-color: #a71818 !important;
            }