I love this wallpaper. Purchased the black version - I would say that the background is a soft, charcoal black (not pure black). We aren't DIY novices, but it was our first time applying wallpaper. I suggest painting your wall dark in case there are a few errant seams. 
I do not understand why there is a repeat on this pattern, as it could be truly random. Especially when peel and stick is billed as a DIY or novice application style. Overall my son LOVES his star wall and I think it looks amazing.