Yeah, I prefer the colour levels without much BG (well, with BG but not big areas with an invisible line). It looks much better IMO. For some decoration you could use the yellow BG.
edit: Dingdong's logs say that he's creating a pink world! :D
I agree with Ferrari12... New packs are harder to notice than new levels. Try to write a proper comment, like "enjoy my pack!" or something. That'll put the pack in the "newly commented levels".
Kiethy, there is, but they used it in the yellow world already.