My theme has a black background so I have edited the plugin to choose the dark theme for the FB Like button.
Is there a less hacky way of doing this?
If anyone else wants to do this here's how I did it:
1. Open /buttons/Facebook.php (I used the Edit form in the Dashboard)
2. Look for the DIV that creates the FB button (about line 79)
3. Add this parameter inside the DIV tag: