Artscow Grey/Bleed Area ?

[atmls99]

I'm trying to make an 8x8 book. I'm using black as my page background and then putting the 4x6 size autograph cards onto the page. It's working great until I notice that Artscow says to fill the grey area surrounding the page with your picture. The page isn't all picture, some of it is black background. Do you think I will have a white border on the pages? Hope this makes sense!