Cocoa Beans

Cocoa beans (also known as the brown dye) are a primary color dye used for making cookies and brown wool.

History
Cocoa beans were initially introduced in Beta 1.2, but were not able to be obtained without an inventory editor.

As of Beta 1.4, cocoa beans were formally brought into the game as a reward found in dungeon chests. (53% chance) Also as of Beta 1.4, brown sheep naturally spawn which made obtaining brown wool easier. In 12w16a, cocoa beans are obtainable in bonus chests. In 12w18a, cocoa beans have a small (0.5%) chance of dropping from destroyed jungle tree leaves in a similar fashion to apples, making cocoa beans a renewable source of material for the first time. Cocoa plants provided an additional way of obtaining them in 12w19a.

Jeb said during his Dreamhack presentation that cocoa trees are pending. Cocoa beans are among the rarest obtainable items on old worlds (after cookies) as they can only be found in dungeons generated after Beta 1.4. The use of cookies as a 'trophy item' gives cocoa considerable value on unmodified servers, even more so than diamonds. With cocoa beans now being obtainable from jungle trees in 12w18a, they are no longer as rare.