Blue Clay colour disappearing in a high lard soap

[mintle]

I have had this idea to make a totally white soap with plenty of lard in it and some colour accent made with blue clay.

I have never before used such high amount of lard (50%) and sunflower (20%). I also used 10% castor and 20% coconut, with water discount (30% lye concentration) and 5% sorbitol as an additive. Scented with a great Nivea FO bought from a reliable supplier (manske-shop.com). I have used this scent in a past and it does not discolour or accelerate trace.

I also coloured a part of soap with 1 teaspoon of blue clay (bought at manske-shop.com), mixed with a bit aof HO sunflower oil. I actually created 2 shades of blue to have some gradual effect in my soap. When I was pouring it at quite a thick trace, the soap had fantastic looks - very white bottom vs blue top with a gradual colour effect. It was 1 teaspoon of clay per approx 150g of oils (overall batch size is 400g of oils).

You have to believe me it was fantastic - I cannot prove it because today when unmoulding I found our that the blue colour is gone! Aaaah. Like totally gone. The soap is really nicely white at the bottom and the formerly blue top is just creamy in colour. Magic especially when you consider how I tweaked my recipe in order to avoid beige creamy colour of the batch :???:

I checked the supplier's site and it says my blue clay consists of kaolin and ultramarine (CI 77007). Kaolin explains the beige-y colour of the top layer.
And is it possible that the particular ultramarine oxide used in the blue clay was simply unstable in the cp process? However CI 77007 should stand for a well-known ultramarine blue which I believe is stable in cp soaps.

I attach photo of my soap which is too dark but does show the colour difference between the white bottom and beige top.

Any ideas what might have happened here?

 

[Alprinceton]

I think, ultramarine oxide turns blue only in less basic (alcaline) mediums.
New soap is highly alcaline.
In a sour environment it comes out blue.

I never got a blue CP soap when using ultramarine blue, (oder purple using ultramarine purple)

Only once, after two years of curing, it turned a little bit blueish, (due to a lower PH value while curing?)

Sorry for my English.
Did I use the right terms?

I like your soap. I can understand your disappointment, since you wanted it BLUE, but I like it anyway

 

[mintle]

Alprinceton, vielen Dank for your answer! I assume ultramarine blue might be just as you say unstable. However, one reliable supplier we have locally claims that this one can be used in soaps. I'm a bit confused.

Your English is perfectly understandable!
Anna

 

[AF_SOAP]

Well good to know I'm not the only one. I was making a Coast looking soap with alternating lines of blue and white and the blue dissapeared like magic and it was this ultramarine blue stuff that I used too.

 

[Kansas Farm Girl]

I got a very nice blue using TKB Trading's Ultramarine blue. I didn't weigh it I just spooned a little into the salt I was using to make the salt bar I wanted. I had not used it before so have no idea if the salt helped keep the color or what, but no problems. It did appear a little blue/green at first but it came through a gorgeous blue after saponification. I will see if I have any pix and post them.