Here is a nice solution using the Gooogle Maps API itself. No external service, no extra library. And it enables custom shapes and multiple colors and styles. The solution uses vectorial markers, which googlemaps api calls Symbols.
Besides the few and limited predefined symbols, you can craft any shape of any color by specifying an SVG path string (Spec).
To use it, instead of setting the 'icon' marker option to the image url, you set it to a dictionary containing the symbol options. As example, I managed to craft one symbol that is quite similar to the standard marker:
function pinSymbol(color) {
return {
path: 'M 0,0 C -2,-20 -10,-22 -10,-30 A 10,10 0 1,1 10,-30 C 10,-22 2,-20 0,0 z M -2,-30 a 2,2 0 1,1 4,0 2,2 0 1,1 -4,0',
fillColor: color,
fillOpacity: 1,
strokeColor: '#000',
strokeWeight: 2,
scale: 1,
};
}
var marker = new google.maps.Marker({
map: map,
position: new google.maps.LatLng(latitude, longitude),
icon: pinSymbol("#FFF"),
});
I you are careful to keep the shape key point at 0,0 you avoid having to define marker icon centering parameters. Another path example, the same marker without the dot:
path: 'M 0,0 C -2,-20 -10,-22 -10,-30 A 10,10 0 1,1 10,-30 C 10,-22 2,-20 0,0 z',
And here you have a very simple and ugly coloured flag:
path: 'M 0,0 -1,-2 V -43 H 1 V -2 z M 1,-40 H 30 V -20 H 1 z',
You can also create the paths using a visual tool like Inkscape (GNU-GPL, multiplatform). Some useful hints: