International travel from the UK has been given the nod to resume from 17 May, the government has announced.
The same colour designation might not apply to the entire country, however.
Israel is the major country with the best vaccine roll-out, and partly because of the success of the programme, case numbers have dwindled sharply since a peak in January.
Travel industry expert Paul Charles believes up to 30 countries will be on the green list.
The Portugal directorate-general of health indicates that parts of Madeira and the main Azores island, Sao Miguel, currently have high levels of coronavirus.
The Italian islands of Capri, Procida and Ischia could make the green list, thanks to an Italian government plan to create “Covid-free islands”.
Micronesia, in the South Pacific, has recorded just one Covid case, and no deaths, while neighbouring Tahiti has announced it will reopen to tourists from 1 May.