Green coffee is decaffeinated before roasting. This process changes the color of the green coffee: it varies from light brown (Natural and CO-2) to green-brown (MC and Swiss Water Process -SWP- decafs). There is another decaf we list as WP, Water Process, which is a water filtration method similar to Swiss Water, but performed at a plant in Mexico. The arrival of decafs always follows the main crop of a coffee by some months, since the coffee needs to be shipped to the decaffeination plant. Oddly, there are only a few such plants in the world, so decaf coffee has to travel a long way usually from origin, to plant and then to the buyer's country. This adds to the cost too, so decafs are often a bit pricier. Here's some decaf roasting basics.