Start by cutting the large 2-lb block of soap base in half (set half aside for later), and cut 1 lb. of the soap base into small cubes. Divide the cubes into three piles.
Place one of the piles of soap cubes into the Pyrex measuring cup, and melt in the microwave in 20-30 second increments, stirring well after each microwave session to ensure that the soap is completely melted.
Carefully mix in Sunset Yellow soap colorant (10-15 drops as needed) and Candy Corn fragrance oil (10 drops) until the desired color/scent is reached, and pour the liquid soap into the mold.
Spray the top of the soap with isopropyl alcohol to break the surface tension and remove any air bubbles, and allow the soap to cool for 20 minutes.
Repeat the process for the orange (Sunset Red mixed with a tiny bit of Sunset Yellow) and white layers, allowing the orange layer to cool for 20 minutes before pouring the white layer. IMPORTANT NOTE: Before pouring the melted soap into the mold, spray the top of the previous soap layer with alcohol again to help the layers adhere together!
Allow the soap to cool until it is completely firm (around 60-90 minutes depending on the temperature and humidity) before unmolding.
Slice the loaf of soap into 5-6 individual bars. Trim the bars into triangle shapes to resemble candy corn pieces.