In a large bowl using a mixer, beat butter with powdered sugar and mint extract until smooth. Add in the green food coloring, and mix until it is fully green.
Fold in the chocolate chips. Roll the mixture into balls, and place onto a plate. Freeze for at least 20 minutes.
Place the chocolate chips into a microwave-safe bowl, and heat in the microwave in 30 second intervals, stirring well until it is fully melted and smooth. Fully coat each truffle into the melted chocolate. Set them back onto plates, and let sit until the chocolate has completely set.
