Place the butter in a saucepan and cook on medium-high heat.
Once the butter melts, pour the evaporated milk into the pan.
Next, add the sugar and mix well. Place the candy thermometer into the pan.
Bring the mixture to a full rolling boil and cook until the thermometer reaches 234-degrees Fahrenheit.
Once the temperature reaches 234-degrees, remove the saucepan from the stovetop.
Add the marshmallow cream and mix until melted.
Next, add the white chocolate chips and mix until melted.
Pour the fudge mixture into three heat-safe bowls in even amounts.
Add some yellow drops of food coloring to one bowl and mix.
Add some red and yellow drops of food coloring into one of the other bowls and mix until it reaches an orange color.
Spread the white fudge mixture on the bottom of a 9-inch by 9-inch square pan lined with parchment paper.
Next, spread the orange layer and finish with the yellow layer on top.
Sprinkle the candy corn on top and allow the fudge to set up for at least two hours at room temperature.