CODE EXAMPLE FOR JAVASCRIPT

leaflet marker cluster change color

.marker-cluster-small {
background-color: rgba(218, 94, 94, 0.6);
}
.marker-cluster-small div {
background-color: rgba(226, 36, 36, 0.6);
}
.marker-cluster-medium {
background-color: rgba(241, 211, 87, 0.6);
}
.marker-cluster-medium div {
background-color: rgba(240, 194, 12, 0.6);
}

.marker-cluster-large {
background-color: rgba(253, 156, 115, 0.6);
}
.marker-cluster-large div {
background-color: rgba(241, 128, 23, 0.6);
}