Anyone heard of this?
http://www.modelingcolors.com/index.html

Wondering how well they work.

I think this is just easy to do it yourself. Buy good pastels, Schmincke as an example, with a wide range of colours. Make them to powder and store them. Mix them if you want for new variations in shades or whatever. Be creative, give it your personal touch.
You can save so much money.

Robert Jan

They look like Tamiya weathering pigments. I buy some pigments and crush my own minerals in a pestle for others.

I generally buy pastels at the large discount art supply store in my part of the world. The pastels come in stick form so I convert them to a brush-able powder by sanding the sticks over a container. I can mix or match any color that I might need. This part of the hobby has become the most relaxing and fun part of model finishing for me. For those of you not near a store there are the discount art supply stores on the internet to satisfy you requirements.

I'm having problems mixing pigment. I use a toothpick as an agitator, but they don't blend well.

I agree with Brent. It is so easy. With some white spirit or turpentine, better is thinner, you can even make paint if you like. Work like Rembrandt, Vermeer in thin layers with something you mix yourself.

Robert Jan