From Fedora Project Wiki
Default Theme Artwork Submissions
Release name for F15 has been selected: it's Lovelock.
We have a special page for the submissions for general wallpaper.
Submit your wallpaper concepts here!
Supplemental Wallpaper Submissions
We have a special wiki page just for uploading your supplemental wallpapers:
Submit your supplemental wallpapers here!
Release Banners Submissions
We have a special page for the submissions for release banners.
Submit your release banners concepts here!