Clay is amazing in soaps! They add a silky glide to soap bars and are an ideal choice as a natural colorant. Use .5-1 teaspoons of clay per pound of soap making oils. Mix well in oil first to remove any clumps, then add to soap.
Activated charcoal gives soaps a deep black color. Mix with oil before adding to soap for the darkest results. Use 1-2 teaspoons per pound of oils.
Indigo is a fantastic natural blue! We have found the best results are achieved when adding to lye water, then adding to soap.