function generateMarker(rgbColor){

    var image;
    //image codes

    return image;
    }

var myLatlng = new google.maps.LatLng(-25.363882,131.044922);
var mapOptions = {
  zoom: 4,
  center: myLatlng
}
var map = new google.maps.Map(document.getElementById("map"), mapOptions);

var marker = new google.maps.Marker({
    position: myLatlng,
    title:"Hello World!",
    icon:generateMarker([125,0,32])
});

// To add the marker to the map, call setMap();
marker.setMap(map);