Cocoa Beans

Coco bean is a material used in Dye-making, introduced in the Beta 1.2 update. It has a dark brown texture and can be used to color wool. Jeb tweeted that he "removed one of the minecraft dyes." This was presumably the brown dye and most likely coco beans will be re-added in a future update. You can currently obtain the Coco Beans only from Inventory Hacking. Hacked-in cocoa beans can be used to dye a sheep's wool brown.