I love working with natural colorants and these supply lots of fun challenges. I've found some good information on a range of natural colours in soap but not many showing how they perform over time. I plan on showing some of these changes.
This lime and ginger soap is coloured with oil soluble annatto extract (orange) and liquid chlorophyll (green).
I stopped colouring with the chlorophyll as I found that unfortunately when exposed to light the pretty apple green breaks down to an unpleasant brown when exposed to light for any length of time.
On the other hand the annatto only fades slowly over time to a lighter orange/yellow depending in the original intensity. The image below shows the brown colouring due to the chlorophyll breaking down .
This 100% coconut oil soap is around 8 months old and had been taken to market so was exposed to short bursts of intense sunlight. I make mostly castille, a little 100% coconut oil and bastille. This discolouration of the chlorophyll for some reason seemed too occur more rapidly with the soaps containing coconut oil in them than the castille.
This blue cypress scented soap was produced by setting up 3 separate in the pot swirls. This was a special soap I made up just for a swap as it is very labour intensive. I also used refined olive oil so I had a white base normally I use extra virgin olive oil which provides a cream soap. The top layer was produced with uncoloured soap and annatto extract
The middle layer was produced using indigo powder and annatto extract. The pretty green is a blend of these two.
The bottom layer was a produced incorporating olive oil infused with alkanet, indigo powder and Australian pink clay. This has been stored in the dark for a couple of months without fading. I'm playing around with using the indigo and annatto blend for a nice green.
I also like to use French green clay for colour. I love this too but this provides a duller earthy green colour that doesn't fade rather than a bright apple green. The only problem is it can also be difficult to source the brighter green French clays. The colour of the tea-tree and lavender scented soap below is typical of green clay coloured soap.
If anyone has used a nice natural apple green that doesn't eventually turn brown I'd love to hear from you.