Google has started highlighting search areas in Pink color. Is this feature available in Google Maps API 3?

Solution 1:

No. It's not available in the API.

(It may be available in the future. Features of Google Maps do migrate into the API, but Google don't make announcements in advance and no-one has a crystal ball.)

You would need to find the city boundaries and draw the line yourself. Boundary data is almost certainly public-domain for the US. Other jurisdictions may not be so forthcoming.

Solution 2:

Although a very old post my answer might help somebody out there as am landing on this post every time I query for bounding box:

Yes we can get the bounding box coordinates that google is using to highlight a region using Googles geocoding service. check for the response of the API call in the below sample from Google.

https://developers.google.com/maps/documentation/javascript/examples/geocoding-simple?refresh=1