icon: 'http://chart.apis.google.com/chart?chst=d_map_pin_letter&chld=1|FE6256|000000'

<hr/>
1. add Google maps script To _Layout page.<br/>
     <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false">   </script >
<hr/>
2. Add script to your view page.

  <script type="text/javascript" ><br/>
   var mapLocation = [['Lucknow', 26.74561, 80.859375],<br/>
                    ['New Delhi', 28.613459, 77.695313],<br/>
                    ['Jaipur', 26.980829, 75.849609],<br/>
                    ['Ahmedabad', 22.674847, 72.333984],<br/>
                    ['Mumbai', 18.760713, 73.015135]];<br/>
    $(document).ready(function () { initialize(); });

function initialize() {<br/>
        var latLng = new google.maps.LatLng(22.917923, 76.992188);<br/>
        var myOptions = { center: latLng, zoom: 10,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        };<br/>
        var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);

        setMarker(map, mapLocation);
    }

function setMarker(map, mapLoc) {
    for (i = 0; i < mapLoc.length; i++) {
        var loca = mapLoc[i];
        var myLanLat = new google.maps.LatLng(loca[1], loca[2]);
        var marker = new google.maps.Marker({
            position: myLanLat,
            icon:'https://chart.googleapis.com/chart?chst=d_map_pin_letter&chld='+ ( i     + 1) +'|FF776B|000000',
            shadow:'https://chart.googleapis.com/chart?chst=d_map_pin_shadow',
            map: map,
            tittle: loca[0],
            zIndex: loca[3]
        });
    }
}

while creating marker use the

<script>
var marker = new google.maps.Marker({
            position: myLanLat,
            icon:'icon: 'https://chart.googleapis.com/chart?chst=d_map_pin_letter&chld='+ (position) +'|FF776B|000000',
            map: map,
                  });
<script>

for i in {1..99}; do curl -o ./${i}_map_icon.png  "http://chart.apis.google.com/chart?chst=d_map_pin_letter&chld=${i}|FE6256|000000"; echo $i; done

https://raw.githubusercontent.com/Concept211/Google-Maps-Markers/master/images/marker_[color][character].png