You can use activated charcoal to get natural black and grey color in your soap. Besides being a natural colorant, activated charcoal has many benefits for skin. Activated Charcoal is the new skin savior.
It has the ability to absorb into the pores of the skin and draw out the dirt and oils that are blocking the pores. Because activated charcoal removes toxins, it can help reduce the instances of acne and other skin impurities.