The Collaborative International Dictionary of English v.0.48:

Buff \Buff\, a.
   1. Made of buff leather. --Goldsmith.
      [1913 Webster]

   2. Of the color of buff.
      [1913 Webster]

   Buff coat, a close, military outer garment, with short
      sleeves, and laced tightly over the chest, made of buffalo
      skin, or other thick and elastic material, worn by
      soldiers in the 17th century as a defensive covering.

   Buff jerkin, originally, a leather waistcoat; afterward,
      one of cloth of a buff color. [Obs.] --Nares.

   Buff stick (Mech.), a strip of wood covered with buff
      leather, used in polishing.
      [1913 Webster]