Gallery background

Hello – Recently just bought this theme, very good.

however there are some things that are quite different from the live demo and the installed one. even if you “quick install” demo content.

I made a gallery, and then posted this shortcode into a page called gallery. However the background is white since i use the Full Page template – and if i link directly(without a page) to the gallery it looks all weird and with a sidebar.

current this is what it looks like:
http://www.obey-guild.dk/galleri/
How do i make the background tranparent like on the demo like here: http://skywarriorthemes.com/orizon/wp/gallery/