I really do not think we should advise you on this. PlantVillage is a resource for reducing infectious diseases of food plants, not for advice on post harvest spoilage. It could be that the green is normal and just a varietal color. It could be some other organism (e.g. fungus) that grew before harvest or after. But given that it could be post-harvest and that identifying it is extremely hard without other sources of data then I would not venture to do so.