Is it possible to make background of jquery picture gallery black instead of semitransparent?

Q: I am testing VisualLightBox out for my own website as well as for work.
Is it an option to make the background (where there are no picure and no controls) black instead of just greyed-out? If I could make it completely black, then I would know people were focussing on my pictures only.

A: Yes, it's possible to make overlay shadow non-transparent. Open generated "vlbdata1.js" file in any text editor (for example, Notepad), find the following parameter:

overlayOpacity: 0.7

and set value "1" for it.