gitlab-org--gitlab-foss/app/assets/stylesheets/pages/notifications.scss

.global-notifications-form .level-title {
  font-size: 15px;
  color: #333;
  font-weight: bold;
}

.notification-icon-holder {
  width: 20px;
  float: left;
}

.ns-part {
  color: $gl-primary;
}

.ns-watch {
  color: $gl-success;
}

.ns-mute {
  color: $gl-danger;
}