title: keep the new background color of current day in fullcalendar when click on next month or previous month
body: <p>I am working on a react project using npm fullcalendar. there is a requirement that I need to change the color of the current day. I managed to do that using the following : </p>
  
  <pre><code>$('.fc-today').attr('style','background-color:#40cc25');
  </code></pre>
  
  <p>however, the problem is that when I click on next month or previous month it change the color to the original color of the library. how can I keep my new background color?
  here is my code :</p>
  
  <pre><code>var EventCalendar = React.createClass({
      mixins: [History],
  
      getInitialState: function () {
          return {
              isModalOpen: false
          };
      },
      _onCalendarSelect: function (start, end, jsEvent, view) {
          if (!AuthStore.isAdministrator())
              return;
  
          var event = {
              start: start,
              end: end
          };
  
          this.setState({
              event: event,
              isUpdate: false
          });
  
          this.props.onNewEvent(event);
      },
      _onEventSelect: function (event) {
          this.props.onEventSelect(event)
      },
      _loadEvents: function(start, end, timezone, callback) {
          var events = EventStore.getInRange(start, end, this.props.environmentId);
          if (!EventStore.isLoaded(start.format("YYYY-MM"))) {
              EventActions.fetchData(start, end, this.props.environmentId)
          } else {
              callback(events);
          }
      },
      _onEventStoreUpdate: function() {
          // This is fix for IE11 required by bug RTC #458121
          var moment = this.$fullCalendarContainer.fullCalendar('getDate');
          this.$fullCalendarContainer.fullCalendar('destroy');
          this.$fullCalendarContainer.fullCalendar({
              defaultView: 'month',
              defaultDate : moment,
              selectable: true,
              eventLimit: true,
              eventClick: this._onEventSelect,
              select: this._onCalendarSelect,
              events: this._loadEvents,
              displayEventEnd: false,
              displayEventTitle: true,
              nextDayThreshold: false
          });
  
          $('.fc-today').attr('style','background-color:#40cc25');
  
          // For other browsers we can just use : this.$fullCalendarContainer.fullCalendar('refetchEvents');
      },
      componentWillMount: function () {
        EventActions.invalidateData();
      },
      componentDidMount: function () {
          this.$fullCalendarContainer = $(this.getDOMNode());
          this.$fullCalendarContainer.fullCalendar({
              defaultView: 'month',
              selectable: true,
              eventLimit: true,
              eventClick: this._onEventSelect,
              select: this._onCalendarSelect,
              events: this._loadEvents,
              displayEventEnd: false,
              displayEventTitle: true,
              nextDayThreshold: false
          });
          EventStore.addChangeListener(this._onEventStoreUpdate);
      },
      componentWillUnmount: function () {
          this.$fullCalendarContainer.fullCalendar('destroy');
          EventStore.removeChangeListener(this._onEventStoreUpdate);
          EventActions.invalidateData();
      },
      render: function () {
          return &lt;div/&gt;
      }
  });
  
  module.exports = EventCalendar;
  </code></pre>
  
  <p>and this how I am calling the componenet:                    </p>
  
  <pre><code>&lt;EventCalendar onEventSelect={this._onEventSelect} onNewEvent={this._onNewEvent} environmentId={this.props.params.id}/&gt;
  </code></pre>