Hi Anne, the majority of John Lewis' sofas are made to order with a wide selection of finishes available. They do, sometimes, though offer a selection of chairs and sofas for 7 Day Delivery with a limited choice of colours because these items are held in stock and it would be impractical to have more than a couple of options.
These chairs and sofas are usually offered at a promotional price and will have finishes that are not part of the normal made to order selection. These examples do sell out fairly quickly and are not usually offered repeatedly. There are some items in the Camber Range that fit this description but, as you may have seen, in Duck Egg, Pink & Natural and not the Soft Green fabric that you are interested in.
So, to answer your question directly, it is unlikely that the Soft Green option will be available again, I am sorry to say.
Kind regards and sorry I was not able to help you.