In a large saucepan over medium-low heat, melt the butter. Once the butter is melted, add in the marshmallows and stir continuously until they are completely melted and the mixture is smooth.

Remove the saucepan from heat and, if desired, stir in a splash of vanilla extract for extra flavor. Gently fold in the rice krispies cereal until it is evenly coated with the marshmallow mixture.

Transfer the cereal mixture into a greased 9x13 inch baking pan. Using a sheet of parchment paper or lightly greased hands, gently press the mixture evenly into the pan to form a smooth layer. Allow it to cool to room temperature.

Once the rice krispie treats have cooled, cut them into squares or use cookie cutters to create fun shapes.

In a microwave-safe bowl or using a double boiler, melt the white candy melts according to the package instructions, stirring in oil-based food color to achieve your desired shade of color.

Dip each rice krispie treat into the melted chocolate, ensuring it is completely coated. Use a fork or dipping tool to remove any excess chocolate.

Place the chocolate-covered treats onto a baking sheet lined with wax paper or parchment paper, allowing them to set at room temperature.