Cream butter and sugars in a large bowl till creamy. Beat in eggs, vanilla, and green food coloring. Add flour, salt, and baking soda. Stir till blended, then stir in the mint chocolate chips.
Drop by tablespoonfuls onto lightly greased or silpat lined cookie sheets.
Bake at 350° for 10-12 minutes.
Notes
The mint chocolate chips are pricey online, so if you can't find them in stores, you can substitute Andes mint baking bits.