there is no grade 1; the lowest is grade 8 and you move up to FIFA. now college and high school may do something different but scysa uses ussf referees that start at grade 8. once again the shirts mean nothing, as said earlier it is a color to differentiate from the teams playing. They told us to get at 2-3 shirts for our ref kit.
I as said refereeing is subjective and refs call things how they see them. The ref should be in control and be neutral but that does not happen all the time.
FYI to all-referees remember teams, coaches, and players and sometimes that can effect things-although it shouldn't-but i saw it in a high school i was watching...first few minutes one ref who had a problem with one team was blowing his whistle and gave a yellow in 10 minutes as a player told his teammates that to play hard as they were not going to get anything..this was not to the referee but he had done stuff in a previous game. As a coach and a ref too, i keep my mouth shut for the most part--