Changing background color in Google Map InfoWindow

I want my InfoWindows in my Google Map implementation to have a black background color. "backgroundColor" is not an available option for InfoWindows. See here.

I put a div tag in the content option with a black background and white text. However, that still renders with a white border.

Does anyone know a way to get a completely black background?

开发者_如何学运维Thanks for any help in advance.

If you want complete control over the background but want the niceties of InfoWindow, then you can can use the InfoBox from the Google Maps Utility library.