CREATE TABLE table_39610 ("Value" CLOB, "Color" CLOB, "Obverse" CLOB, "Reverse" CLOB, "First issued" FLOAT)

When was Color of green first issued?
SELECT MIN("First issued") FROM table_39610 WHERE "Color" = 'green'
SELECT MIN("First issued") FROM "table_39610" WHERE "Color" = 'green'