This is how you change the pop-up info bubble colors!

Add this to your css file and make sure to change the colors to your own schemes!

/* Change the font color in the Google Map (GMap) pop up info bubbles. */
div.gmnoprint {
color: #000;
background: #fff;
}

/* Change the link colors in the Google Map (GMap) pop up info bubbles. */
div.gmapnodelabel.gmapnodelabel-icl-class a {
color: #3879d9;
}

If you change the background color, it also changes the transparent color behind the zoom in buttons and credits in the Map window.

I got the information about what div my bubbles were appearing in by using Google Chrome. I right clicked on top of the pop-up window and selected "Inspect Element." On the bottom of the new window, I looked at the div squares until I found the one that was controlling ALL the links in the pop-up window. If you don't, you'll only get one link to change color, for example. This takes some try and try again effort to find the right div, but when you do, it's magic!

If you have more than one map on the site, check those after doing the above to see if they need to be specifically styled in the CSS too.

Good luck!