[Cob] Pigments in cob?

[Amanda Peck]

Lots of colors die in lime, if you're using a lime plaster.  (see what 
happens, check your signature, let us know).  Woad might even be pH 
sensitive as a color.

I have a project--long overdue, in which I'm planning to use concrete color 
with clay.  But I haven't even done samples with that.  I do know that not 
much lime turns red clay to quite a light pink.  Haven't tried any other 
coloring agents.
.............
Peter wrote:

I have a small quantity of Woad set aside and I'm curious about adding it to 
a mix for a gazebo project this summer. I thought the nice blue would be 
interesting.

Has anyone done colouring with Woad or other pigments in the past?

Any things to consider?


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[I believe that this is what they call the signature--someone will tell me 
if it isn't]

I haven't failed, I've found 10,000 ways that don't work.

Thomas Edison (1847-1931)