.wpcf7-not-valid-red {
  color: red !important;
  background: url('https://mayalania.com/wp-content/plugins/contact-form-7-international-telephone-input/frontend/lib/img/cancel.png') 97% no-repeat;
  background-size:  auto 70% !important;
}
.wpcf7-not-valid-blue {
  background: url('https://mayalania.com/wp-content/plugins/contact-form-7-international-telephone-input/frontend/lib/img/checked.png') 97% no-repeat;
  background-size:  auto 70% !important;
}