Google Maps v3 API and WordPress ACF: Multiple Custom Markers
Charlotte, you could add a "data-marker" attribute to each of your marker objects as you build the markup, like this (green/grey wherever you need them)
<div class="marker" data-lat="<?php echo $location['lat']; ?>" data-lng="<?php echo $location['lng']; data-marker="green/grey" ?>">And then in the javascript you can check the marker type using the data-marker you set in the code, like this
var grayCircle = { //path: 'M -1,0 A 1,1 0 0 0 1,0 1,1 0 0 0 -1,0 z', path: google.maps.SymbolPath.CIRCLE, fillColor: '#888888', fillOpacity: 1, scale: 3, strokeColor: "#888888", strokeWeight: 3};var greenMarker = //create your marker here//Check your marker type, if it's green then set that otherwise leave it greyvar markerType = $marker.attr('data-marker')=="green"?greenMarker:greyCircle;var marker = new google.maps.Marker({ position: latlng, //Set your marker using markerType here icon: markerType, map: map});