Jquery LIghtbox for Native Galleries help….

I am having trouble finding out where I need to go to edit the lightbox used with the Jquery Lightbox for Native Galleries Plugin. What I want to do is be able to change the color of the frame of the lightbox as well as regulate the height of the images. It seems when I have an image in landscape (horizontal) format, everything is fine, but when I have an image in portrait (vertical) format, the images are way too big. Any ideas would be greatly appreciated.

My blog is http://www.colbybrownphotography.com/blog/