FRONTEND_MVC/web/js/zuck/dist/skins/facesnap.css

.stories.facesnap .story > .item-link {
  text-decoration: none;
  color: #333;
}
.stories.facesnap .story > .item-link > .item-preview {
  border-radius: 50%;
  padding: 2px;
  background: #3b5998;
}
.stories.facesnap .story > .item-link > .item-preview img {
  border-radius: 50%;
  border: 3px solid #fff;
}

.stories.facesnap .story.seen {
  opacity: 0.5;
}
.stories.facesnap .story.seen > a > .item-preview {
  background: #999;
}