My take is that the Rebel pilots are in the last version of flight gear Republic Navy pilots wore and that in the ten or so years since the declaration of Empire, entire squadrons had defected.
Regarding the "Rebel Fleet Trooper", my reasoning is that, after the Emperor dissolved the Imperial Senate, Republican Senators (the ones we saw in the deleted scene from ROTS plotting rebellion, and others who came to agree with them over the years of Palpatine's tyrrany) had made their way to the Alliance's primary base, with their still-loyal Senatorial Guard retinues. I consider the green-uniformed Rebels to be the ones in Alliance uniform in the award scene. Remember, at the time, they wouldn't know Leia had been captured, that the Falcon was leading the Death Star to Yavin, etc.
In the years after the victory immediately prior to that film, the destruction of Alderaan, and the Rebels, in turn, destroying the Death Star, they had to have gained legitimacy in the eyes of the galaxtic populace, especially away from the Core. With more recruits and more resources, they'd be able to come up with a proper uniform. The stuff on Hoth would be their cold-weather gear, the tan fatigues Luke wore would be, essentially, BDUs for (at least) Pilots, and, for all we know, the uniform we see in Jedi could have been adopted about the same time as the "Class A". New uniforms for a new Republic.
--Jonah
Regarding the "Rebel Fleet Trooper", my reasoning is that, after the Emperor dissolved the Imperial Senate, Republican Senators (the ones we saw in the deleted scene from ROTS plotting rebellion, and others who came to agree with them over the years of Palpatine's tyrrany) had made their way to the Alliance's primary base, with their still-loyal Senatorial Guard retinues. I consider the green-uniformed Rebels to be the ones in Alliance uniform in the award scene. Remember, at the time, they wouldn't know Leia had been captured, that the Falcon was leading the Death Star to Yavin, etc.
In the years after the victory immediately prior to that film, the destruction of Alderaan, and the Rebels, in turn, destroying the Death Star, they had to have gained legitimacy in the eyes of the galaxtic populace, especially away from the Core. With more recruits and more resources, they'd be able to come up with a proper uniform. The stuff on Hoth would be their cold-weather gear, the tan fatigues Luke wore would be, essentially, BDUs for (at least) Pilots, and, for all we know, the uniform we see in Jedi could have been adopted about the same time as the "Class A". New uniforms for a new Republic.
--Jonah