The database on this site has the F-35 Demo Team frequency as 255.15. I haven‘t seen their demo yet but if it’s just one aircraft, I’m not sure what they’d use the UHF frequency for. Typically I only hear the single-ship demos communicating with Air Boss on VHF.
They’ll use it for a/a transiting to/from show and they also have a spotter on the ground who will talk to the pilot during the show. Mostly the pilot reporting every thing is good after the maneuver. However, the F-35 team has changed their base from Luke to Hill so the a/a aforementioned may not be used this year.
For this year:
372.175—F22 Demo
384.55—-F16 Demo
122.475—A10 Demo