Often times, soap makers (and candle makers for that matter) are trying to color their soaps (or candles) a color other
than white. Whether it's adding a purple swirl, or a bright yellow tint, or green speckles, or layers of orange and red...we're starting with white and making it something different. But white can be a really nice component to a soap design - you just have to plan ahead a bit. But we're not talking about just plain white soap
. This soap is actually a two-color swirl - using white as one of the colors. You can use the exact same technique to do a two-color swirl with two other colors.
This swirl technique would be called an "in-the-mold" technique, similar to the slab mold swirl, or even the column mold swirl.