I'm not sure if this is possible with Google Maps API, but is it possible to add several layers to a map?

For example, I want to have a map that shows several neighborhoods, and want to use darkened layers to allow the "hiding" of neighborhoods, to only show one.

What I'm doing right now is putting each map separately, using Photoshop to hide everything but the neighborhoods, like so:

Not ideal, so if there is a way, it would be great!