MarsSeed [1] filed a deletion request for gnome-mplayer-light-theme [2]: Broken, unused package from 2015.
Repo carries a working gnome-mplayer (same pkgver, but patched to keep it alive). [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/gnome-mplayer-light-theme/
