For this project, I made two bars (4 oz. each) of red chunks and two bars (4 oz. each) of green chunks.
Weigh the soap and put it into your measuring cup. Melt it in the microwave, stirring every 45 seconds or so. Once it's completely melted, add your fragrance oil and colorant. I used about 8 drops of Liquid Red colorant and 1/4 teaspoon of GemTone Ruby Mica.
Stir the colorant and fragrance into the soap and pour it into the mold. Wash out your measuring cup, and repeat for the green bars.
Set the soap aside, or pop it into the refrigerator to cool.