I'm wondering if this would be better served in a big thread about differences in pigment hues, so we can have a big discussion, but I have a question or two about Cobalt Green.
I'm looking at buying this colour, in oils, by Williamsburg:
It's PG50 Cobalt Titanate Green. Williamsburg calls it Cobalt Teal.
This is how the same pigment looks from some of the other manufacturers who carry it. Here we have Blockx Cobalt Green Light, Old Holland Cobalt Green and W&N Cobalt Turquoise Light.
They all look quite different, as you can see.
My question is why? What happens to the Cobalt Titanate Green that it can take on so many different hues?
Second, if I were to buy some of this pigment dry in order to save money, is there anything I can do to the pigment to change its colour? For example if I got a Cobalt Titanate Green powder that matched the Old Holland, is there a process that I could go through at home with the standard safety equipment (Gas/dust mask, gloves etc) that would change it to look like the Williamsburg or vice versa. I know this is a long shot since I don't have a laboratory, but maybe there's a trick.
I understand some basics about changes in hue with the same pigment. I know that PR101 depends on such factors as pigment hydration to give it its different shades, and that PBr7 actually encapsulates a number of different earths, both synthetic and natural, but I have no idea about the Cobalts.