Military clothing is clothing with a purpose - perhaps the greatest purpose of all. Two groups of people are the single largest purchasers of military clothing - retired and active military personnel. Active military personnel are issued certain articles of military clothing and are supplied with what basics they will need during service. However, there are some pieces of clothing, such as a marine's dress blues, that must be purchased individually.
Military clothing is manufactured by several companies in the US with each of them always vying for a contract with one branch or another of the US military. The most popular color of military clothing is olive drab. The most frequently seen pattern is of course camouflaged. In terms of military clothing and official uniforms, besides olive drab, you'll find navy blue and white depending on what branch of the military is present.
Individuals who aren't even military often wear casual military clothing, such as the olive drab T-shirt or camouflage work pants. This is partly why the official uniforms of the US military are so important as they identify an individual's branch of service and rank. A member of the military would quickly know if they were approaching a superior by what they were wearing. A civilian on the other hand may have no idea what rank or branch a uniformed person serves in.
Because there are so many manufacturers of military clothing and military style clothing is popular today, it's pretty easy to find genuine desert and jungle camouflage pants and olive drab shirts and coats. Many T-shirts are screen printed with some reference to the US Army or another branch of the military. Some people debate whether it is appropriate for civilians to wear articles of clothing originally designed for the military, where others believe it is a showing of support for our past and present service men and women.