Flak Jacket

Flak jackets are usually worn by chūnin and jōnin over their normal clothing in most villages, although the design varies among the villages. Although they are called jackets, they look more like a vest, or other similar garments. The jackets are among the most iconic pieces of shinobi equipment. Most of them have pockets, which can be used to store scrolls and also allow a ninja to access them with only one hand, as seen with Kakashi's case when he normally does this secretly to extract a kunai.

Styles
Each village has a different versions of this:
 * Konohagakure flak jackets are green. They have three scroll pouches on each side of their chest for scrolls, medicine, and other ninja tools. For protection they include a neck guard and extra padding over the shoulders. Newer versions feature pockets. They also have a zipper down the middle. The crest of Uzushiogakure is integrated onto the back of the jacket, symbolizing the ties Konoha had with the former village.
 * Sunagakure flak jackets are beige. They may or may not include shoulder padding, shoulder guards, neck guards, and scroll pouches over their stomachs.
 * Iwagakure flak jackets are brown with only one sleeve on the left arm. They have a large pouch over their stomach or the lower back of the vest.
 * Kirigakure flak jackets are slate grey. They come with or without a neck-guard but have elongated padding over the shoulders.
 * Kumogakure flak jackets are white. They have a rather utilitarian version with its only distinctive feature being that it has only one strap to hold it in place.
 * Otogakure flak jackets are black. They seem to have belt-like clasps incorporated into their design and have a pouch in the front.
 * In the anime, Takigakure flak jackets are sky blue. They are otherwise identical to Konoha's flak jackets.
 * In the anime, Hoshigakure flak jackets are blue. They have two scroll pouches near the hip and are held together by three straps by the neck-guard.
 * In Naruto Shippūden 2: Bonds, the Land of the Sky flak jackets are purple with two basic pockets on both sides of the chest. They also bear their village symbol integrated onto both of the shoulders.

Trivia

 * Certain shinobi are seen wearing different variations of their village flak jacket; specific variations include no shoulder padding, neck guard, or even pockets.
 * In the manga, Iwagakure shinobi appear to wear red long-sleeved undershirts. However in the anime, they appear wearing brown undershirts. Oddly, Akatsuchi and Kurotsuchi seem to be an exception, as they appear in the anime with red undershirts while background Iwa shinobi wear brown.