CREATE TABLE table_39611 ("Value" CLOB, "Color" CLOB, "Obverse" CLOB, "Reverse" CLOB, "First issued" FLOAT)

When was Color of green last issued?
SELECT MAX("First issued") FROM table_39611 WHERE "Color" = 'green'
SELECT MAX("First issued") FROM "table_39611" WHERE "Color" = 'green'