I watched ep 20 again and saw the photo when Shinn and rest graduated.
One thing got my interested. Why is Meyrin uniform Orange?

Thought it went like this:
Green: Common Soldier/MS pilot
Olive: Terrestrial soldier
Red: Elite soldier/MS pilot, these "elites" are presumably graduates with top marks from ZAFT's training academy.
Black: Junior Officer
White: Command-level Officer
Purple: General/Member of the PLANT Supreme Council/FAITH operative (with FAITH emblem)

Perhaps it was discussed in the ep disscussion of the ep but its gone now so any ide why?
Green wasn't fashionable enough? She wears green uniform in seed otherwise.