You can see on this page: http://www.middlegray.net/ceremonies/
the photos have a white box that is automatically applied to the pic. I want to take it off or make it a different color. Where would I look to change that?
add this to your css file
You could also check the preferences of the gallery to see if there is a way to disable
Can you post your themes functions.php file in an edit on your question. you may be able to filter it out since the theme does a rewrite of the gallery