What does the green list mean for travel? The traffic light system will introduce a green list, amber list and possibly updated red list of countries, with each colour meaning different rules for testing and quarantining. AdvertisementWhich countries are on the green list? AdvertisementHowever, those with a more optimistic view have predicted that as many as 30 countries could be categorised as green when the announcement is made. When will the green list be announced?