Strange border around popped modal ALL BROWSERS

I have a very odd border line showing up around the outside of the colorbox modal in all platforms in all the popular browsers (starting with Chrome). I have dug through the CSS via Chrome inspector and can not find where this is showing up. Can you take a peek and see if you can track it down?

Screenshot of line (from Chrome, but on all browsers):
https://www.dropbox.com/s/c1m0f5i7e0t1qeb/Screen%20Shot%202015-09-06%20at%2010.07.42%20PM.png?dl=0

Link to live site with issue:
http://www.chrisrmiller.com/portfolio/key-ingredient-indiegogo-1/
(click thumbnail down below page description for modal)

FEATURE REQUEST:
You should add in the ability that when the modal is “Opened” that it “freezes” the page behind it. You can currently scroll the page behind the modal while the modal is open. You can eliminate this by adding a jQuery line to the “open” function that changes the body css element “overflow” to “hidden” then on modal “close” it changes it back to “auto”. I am in the process of modifying your code to include this for myself.

https://wordpress.org/plugins/wp-colorbox/