how to customize boot menu and login page in fedora

how to customize boot menu and login page
installing new icons and themes

Here is an article from Fedora Magazine on boot themes


and here is a comment on changing the login page

Modern gnome-shell themes are stored as .gresource files (/usr/share/gnome-shell/gnome-shell-theme.gresource). Most modern Gtk themes (eg. Materia (formelly Flat-Plat), Pop, etc.) provides .gresource files that can replace default theme. Install them on /usr/share/themes, replace the default theme with:

sudo cp -b /usr/share/themes//gnome-shell/gnome-shell-theme.gresource /usr/share/gnome-shell/gnome-shell-theme.gresource

and finally restart GDM.