Jansamn Disconnect MFL 1/4 Thread, Ball Lock Fittings, with Hos Keg Couplers, 4 PCS, Gray

I need Europe parts

What size hoses are they suitable for?

Which color is for gas and which one is liquid?

When screwing on the barbed fitting, is teflon tape needed on the threads or does the litttle rubber seal work sufficiently for a good seal?