Bail wears this outfit during the senate scene where Palpatine declares the restructuring of the Republic into the Galactic Empire.
It consist of a sage green (leaning towards grey) jacket and pants with a large X shaped metal frame over chest and upper back to which the aqua velvet cloak is attached. The cloak is lined with a lighter colored fabric. He wears black boots to all his ROTS costume, a belt around the waist with the Royal Alderaanian symbol, metal gauntlets on both arms, and the collar of the jacket have a metal band as decoration.