We took Sky Princess on December 16 then switched to Emerald Princess on December 23, both out of Fort Lauderdale. We did not have medallions, we were blue on the 'old' app, we did not have any type of electronic boarding pass, just passports and a paid up reservation. Lines to board were pretty lengthy and I noticed little if any differnce between blues and greens. Just go and you'll be processed without any problems. Old and new apps work fine on the ships... at least for us.