You can't ... not "per se".
What you can do is to copy the folders
to the users home, run a chown <user> over
them, and that should do ... howver, this is
not dynamic. If you want the changes that
you make in root's KDE settings to be distributed
to all users every time you'll have to write
a script for that :} (one that get's run whenever
root exits a login-shell, for instance)...