Red cabbage pigment.
It's fugitive, meaning it won't last long, it isn't light fast.
And it's PH sensitive, meaning it's blue or purple when it is neutral, pink when there is an acid present, and yellow or green if it is base.
It's a kind of magic.
This morning's moon in a blue, blue sky.
This afternoon's blue, blue sky and a field, or a meadow.
The pigment strained. It needs just a little more prep work and then it will be ready for mark making...