For those interested in using spirulina in cold process soap for color...I would suggest that you do not bother. The soap below was made March 15 and you can see the picture on the bottom how bright the green swirls were. The photo on the top was taken to show you all that after a little more than 2 months the green has faded to a pale green/tan color. Very disappointing...though I have found that stinging nettles makes a really great natural green color that lasts. Now I need to find something else to do with all my spirulina powder. Maybe it would work as a colorant in lotion...but would people want to rub a green lotion all over their body? Maybe it could be marketed for children.