Most distro's that ship Plasma Desktop as .. well, as a desktop to work in, have their own default wallpaper choice that isn't exactly the upstream default. OpenSUSE has things with geekos (which I personally really like, for their understatedness). KDE neon goes for the upstream default, but that is the nature of that particular distro.
The FreeBSD packages of KDE4 had a nice variant of vertical blinds (here's the OpenSUSE variant -- FreeBSD is blue and with a FreeBSD logo). I think that was done by Ivan. However, we're getting close to a release of Plasma 5 Desktop and workspaces as well as KDE Applications for FreeBSD, and it's time to think of a new default wallpaper for the FreeBSD packages. Something lightly branded. So this here is a call for contributions for a KDE-FreeBSD wallpaper for use with the first (FreeBSD) release of the current generation of KDE software.