Add chocolate wafers to the top half of a double boiler. Heat water in the lower half of the double boiler over medium heat. Stir until chocolate is melted. Remove from heat.
Set aside 1/4 of the melted chocolate for the white chocolate stripes.
Add green gel food coloring, stirring well until the designed shade of green is achieved.
Pour a layer of the green chocolate into each of the molds (following the mold directions for the amount).
While the chocolate in the mold is still warm, add 1 Oreo cookie to each mold.
Pour more of the green chocolate to cover the top of the Oreo.
Place mold on a cookie sheet and put in the freezer for 2 hours or until firm.
Remove from freezer and gently pop the chocolate covered Oreo cookies out of the mold.
Reheat the melted white chocolate if necessary.
Spoon melted white chocolate into a plastic baggie or pastry bag.
Drizzle the melted white chocolate on top of each of the green chocolate covered Oreo cookies.
Notes
Store in an airtight container at room temperature for up to 2 weeks.