Melt butter in a large saucepan over medium heat.
Stir in the marshmallows just until melted.
Take off heat and add orange (or red and yellow) food coloring until desired color is reached.
Stir in Rice Krispies until coated.
Generously spray a sheet pan with nonstick spray and pour the Rice Krisipe mixture into the pan.
TIP: wet your hands with water before pressing down the Rice Krispies into the pan so they won't stick.
Once cool, cut into long triangles.
Melt white chocolate in the microwave at 30-second intervals, stirring between each. Color with food coloring. Pour into a piping bag or sandwich bag with a corner cut off.
Pipe over the Rice Krispie triangles and let set.
Use leafy greens for an accent as the carrot stem.