I'm not sure if enough information is given in the profile template data to identify if a users profile belongs to a mod or admin to use a template switch - then it is just a matter of styling. If not, then you need a extension (or code hacking aka mod, which is deprecated in 3.1-series).
Any special reason for your request? Nobody can ignore a admin (or a moderator) in the current implementation, so pressing the "foe"-Button gives a error message.
For a friend - why will you not allow to make a admin your friend? The "Friend"-Status is actually just a help to address PMs quicker. (And a admin as a friend is much better than a admin as a foe