Because it's worn uniformly by all personnel in the Army.
The uniform was first fielded in April of 2005
There is no flag on the dress uniform
No the CIB is a an Army award and not transferrable to the Marine Core dress uniform.
You get several different types of uniforms - PT uniform, dress uniform, ACU uniform, etc.
Army green with a special hat (and a gun!)
A person does not get a uniform before boot camp in the army reserve. A uniform is handed out during the Reception Battalion, referred to also as week zero.
On social occasions when the prescribed uniform is the Army Blue Uniform, personnel who don't have one are authorized to wear the Army Green Uniform with white shirt and bow tie.
Green
Armani
Yes.
No.
It is called an uniform