Is there a way to mark areas with multiple markers?

In my project users make reports and leave a marker on the map. I was wondering if it was possible to mark the zones with more markers in the map with different colors. Thanks

Below I wrote a part of my javascript code (also because StackOverflow doesn't let me insert everything). You can view the data on the database and insert the marker on the map. Markers are automatically inserted when the site starts. I would like to mark the area with more red marker for example.

var map;
      function initMap() {
        map = new google.maps.Map(document.getElementById('map'), {
          center: {lat: 45.6140747, lng: 8.8427703},
          zoom:14
        });
        var markerCluster = new MarkerClusterer(map, markersArray,
           {imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m'});


      }
      function clearOverlays() {
        for (var i = 0; i < markersArray.length; i++ ) {
            markersArray[i].setMap(null);
        }
        markersArray.length = 0;
        }





        $( document ).ready(function() {
    dbRef.on('value', function(snapshot) {
      snapshot.forEach(function(child) {
      var childs=child.val();
       //var dataSegn = new Date(childs.data2.year,childs.data2.month,childs.data2.date);
       var contentString = 'Segnalazione del: '+childs.data+'<br>Per: '+childs.motivo+'<br><img src="'+childs.urlimmagine+'" alt="Foto" style="width:200px;height:300px;">';

       var infowindow = new google.maps.InfoWindow({
           content: contentString
           });

      if(childs.motivo =='ESCREMENTI') {
      var marker = new google.maps.Marker({
          position: {lat: childs.lat, lng: childs.lon},
          map: map,
          title: childs.motivo,
          icon : 'http://maps.google.com/mapfiles/ms/icons/green-dot.png'
          });
          markersArray.push(marker);
          marker.addListener('click', function() {
          map.setZoom(16);
          map.setCenter(marker.getPosition());
          infowindow.open(map, marker);
        });
      }
      if(childs.motivo =='PERICOLOSI'){
      var marker = new google.maps.Marker({
          position: {lat: childs.lat, lng: childs.lon},
          map: map,
          title: childs.motivo,
          icon : 'http://maps.google.com/mapfiles/ms/icons/blue-dot.png'
          });
          markersArray.push(marker);
          marker.addListener('click', function() {
          map.setZoom(16);
          map.setCenter(marker.getPosition());
          infowindow.open(map, marker);
        });
      }
      if(childs.motivo =='RANDAGIO'){
      var marker = new google.maps.Marker({
          position: {lat: childs.lat, lng: childs.lon},
          map: map,
          title: childs.motivo,
          icon : 'http://maps.google.com/mapfiles/ms/icons/red-dot.png'
          });
          markersArray.push(marker);
          marker.addListener('click', function() {
          map.setZoom(16);
          map.setCenter(marker.getPosition());
          infowindow.open(map, marker);
        });
      }
      if(childs.motivo =='MALTRATTATI'){
      var marker = new google.maps.Marker({
          position: {lat: childs.lat, lng: childs.lon},
          map: map,
          title: childs.motivo,
          icon : 'http://maps.google.com/mapfiles/ms/icons/yellow-dot.png'
          });
          markersArray.push(marker);
          marker.addListener('click', function() {
          map.setZoom(16);
          map.setCenter(marker.getPosition());
          infowindow.open(map, marker);
        });
      }
        });
        });