Updated: Jul 8
After completing my first experiment with coloring soap with clay, I decided to take it a step further and try a few powdered colorants as well.
The powders that I tested for this experiment were indigo, paprika, activated charcoal, madder root, turmeric, wheatgrass, alfalfa, spinach, chlorella, spirulina, matcha, green tea, cranberry, hibiscus, beetroot, and celery. The soap recipe included 67% olive oil, 25% coconut oil, and 8% castor oil with 5% superfat. Although olive oil and other oils/butters naturally change the color of my soap, I was more focused on not having fragrance oil play any part in the color so there was no fragrance added.
After mixing my soap, I first poured my "control" soap so that I would know what the soap would look like with no additives. For these bars, I settled on 1 tsp of colorant per pound of soap and to make them disperse easier, I mixed together 1 tablespoon of sweet almond oil with each teaspoon of colorant. Below are photos of the soap when it was first poured. Spirulina and indigo were definitely my favorite colors to start with.
Of course I read that some of the powders I chose would not work but I wanted to see just how bad they might turn out. Three of my favorite powder colors (cranberry, hibiscus, and beetroot) did not have the effect that I hoped for as seen in the photo below.
I would call the powders above "mild failures" but Matcha and green tea were by far the most disastrous. I don't see myself ever using these powders in soap again.
Once all of the soaps were poured, I let them sit uncovered in the mold for 48 hours then waited the full 6 weeks of curing time to see what the final colors would be and here are my results:
Note: You can also achieve different hues of the colors shown by simply adding more or adding less colorant.