At the time the coconut is harvested, its outer husk is still green. This husk is peeled off the inner nut and in many cases it just stays in the coconut plantation for years. Only a small percentage is used to produce Coco-fibre or Coco-chips.
Some companies use the fresh green husk because it is easier to process. Dutch Plantin prefers the older, woodier and therefore more stable, brown husk. The cocopeat products made from these older husks are therefore more stable too.