I have finally found this natural colorant which I have been looking for so long!
I have read that in soap, alkanet root will yield shades of pink, blue, and purple, depending upon the amount used, types of oil used, and the alkalinity of the soap. Really impressed about the fact that the type of oil would influence the colour, I started experimenting. This soap contains: coconut oil, palm oil, cacao butter, olive oil, sunflower oil and of course alkanet roots infused in olive oil which I added at trace.
The most suitable essential oil to this purple was of course the lavender one.
I am curious to see how long this lovely colour will last.