It appears the manufacturer did not list the pigment(s) for this paint.
This color is different every year, as it is made from the pigments collected from the air filtration system at Gamblin. This mash of color equals out to be a sort of grey, hence the name. It is actually somewhat difficult to get a tube of this, as every year a person needs to find an art store who is receiving tubes of this color. You can ask in the spring, as the opportunity to buy it is usually around Earth Day in the U.S. (April 22).