All of the pumpkins are edible. Do not let anyone tell you any different. I have baked the dark green one here and it had tons of meat. Almost all of the inside is a "dark" orange meat. The skin bakes very soft to. When I dehydrated and blended for storage, I tried it in my pumpkin drink with chocolate and it was not good. Very strong taste, but I baked some Pumpkin muffins with it and they are heavenly. So, the green bumpy pumpkin is worth it's meat in the cash you pay for it and is only good for baked goods.
The grey pumpkin I have not baked and tasted yet. Will let you know asap. I did bake the orange bumpy ones.
Do not forget the seeds. You can toast them to eat and or save some to grow more pumpkins yourself. I gave many toasted pumpkin seeds as gifts for the holiday.