All of the Green Set carols have a demonstration video. You can listen to O Little Town of Bethlehem, Away in a Manger, While Shepherds Watch Their Flocks by Night, Hark! the Herald Angels Sing and Joy to the World.
All of the carols use both hands with more chords in each hand. Very musically satisfying; a significant step forward from the Yellow Set. The sheet music is available for purchase here.