需要 openSUSE Tumbleweed ，用 root 執行：
zypper addrepo https://download.opensuse.org/repositories/home:manfred-h:X11:xfce:4.18/openSUSE_Tumbleweed/home:manfred-h:X11:xfce:4.18.repo
zypper refresh
zypper install greybird-theme
需要 openSUSE Slowroll ，用 root 執行：
zypper addrepo https://download.opensuse.org/repositories/home:manfred-h:X11:xfce:4.18/openSUSE_Slowroll/home:manfred-h:X11:xfce:4.18.repo
zypper refresh
zypper install greybird-theme
需要 15.6 ，用 root 執行：
zypper addrepo https://download.opensuse.org/repositories/home:manfred-h:X11:xfce:4.18/15.6/home:manfred-h:X11:xfce:4.18.repo
zypper refresh
zypper install greybird-theme