Place the chocolate chips into a microwave-safe bowl, and heat in the microwave in 30-second intervals, until it is fully melted and smooth. Divide the chocolate between two bowls.
Stir blue food coloring into one bowl, and green food coloring into the other bowl.
Use a fork to fully coat each Oreo cookie into the blue chocolate, set onto plates. Spoon or pipe the green chocolate onto each cookie. Let sit until the chocolate has completely set.