Melt 10 oz. of glycerin soap in a small pyrex glass cup. Stir until melted. Stir in the green pigment until thoroughly mixed (maybe 1/2 tsp. of pigment). Pour the soup into the mold. Let it set before going to the next layer. The green and white layers should be thin. You only need a little bit.
Melt 1 cup of goats milk base. Pour on top of the green soap layer. Let it set.
Melt 1 pound glycerin soap base. Stir in your fragrance oil and 2-3 drops of red gel coloring until combined. *You can add fragrance oil in each layer or just the biggest layer. *You can also add poppy seeds to make the soap look like watermelon seeds. Fill the soap to the top mold and let it set for a couple of hours.