I think that PC Boxes in Pixelmon should be able to have wallpapers like the PC Boxes do in most of the Pokemon games. Here's some pictures of what I mean:
I made these.
Luvdisc Oceans
Spheal Snowland
Jirachi
Pixelmania Helper+ [January 9, 2015 - June 29, 2016]
Primal Wars Moderator [June 29, 2016 - ]