I found some photos of the Pontifical Gendarmerie's swearing in ceremonies on Google. (serves as Vatican police force today) And you can see a couple of the corp's members wearing the historical uniforms. So they still use the old uniforms at formal ceremonies such as this one: http://www.catholicpressphoto.com/servizi/2007-09-30-festa-gendarmi/default.htm
Once a year a few of them wear the historical garb for a private beginning of the year ceremony in the Vatican.
addendum: note the palatine guard on page 4