#calendario{
  display:none;
}
.fc-ltr .fc-basic-view .fc-day-top .fc-day-number {
    float: right;
    color: #000;
}

.fc-unthemed thead,.fc-day-header, .fc-widget-header, span{
    color: black;
}

<script>
        $(document).ready(function() {
          $('#calendar').fullCalendar({
            height: 250,
            contentHeight: 273,
            editable: false,
            eventLimit: false,
            eventColor: '#dd6777',
            color: '#000'
          });
        });
        $('#calendario').on('shown.bs.modal', function () {
        $("#calendar").fullCalendar('render');
        });

        $("#button").on("click",function(){
        $("#calendario").modal(open).show();;
        });
   </script>