Man, it feels like I haven't posted in months. Oh wait...
Anyway, though I have every intention of delving into each of the items individually and in great detail it’s always good to take a look at the whole outfit. Starting from the head the uniform seems to consist of:
Hair (most people wear nothing on their head) or a helmet with a brown stripe.
Something around the neck, a bandana, scarf, that kind of thing. Almost every character has their own variation.
A shirt, I suppose. Brownish? Maybe black? Probably anything dark in color works.
A red vest with gold stripes.
A long garment. This includes either the smock thing worn under the vest, or the trademark brown coat worn both over and under the vest.
Armor on the arms. Some do, some don’t.
The Serenity ‘Verse seems to be a fairly cold place. Everyone is wearing gloves.
Khaki/tan pants, most with brown piping.
Belt
Leg wrappings. Again, it must be cold everywhere they decided to fight.
Boots or shoes.
War gear. There are soldiers with on their belts, cross slung satchels, tactical vests, etc. in addition to their weapons.
This Firefly Wikia sketch gives a fairly decent snapshot.
