Update 2021-04-19: According to media reports, Greece has changed its regional risk classifications. The islands of Thassos and Kythnos, the municipalities of Rethymno, Phaistos, Maronia, Didymoteicho, Pydna, Kavala, Volos, Sintiki and North Tzoumerka are classified as very high-risk (dark red). Likewise, Mykonos, Leros, Karystos, Kymi, Skyros, Lokres, Agistri, Kythira and Hydra have been classified as high risk (red). For details on the restrictions in “red” and “dark red” areas see here (in greek).