Grind your chalk with a little water just like in the first experiment. This paint will dry to a glossy finish. Try mixing different-colored chalks. One red stick of chalk and another that's yellow should give you orange paint. Experiment on your own with vehicles and pigments.
Soft rocks are good for some colors.
The soot from inside a fireplace will give you black. An important part of art is experimenting. All paint is solid pigment floating in a vehicle. A colloid is when one kind of thing is floating evenly in another kind of thing. There are lots of other colloids.