If you took all the pigments in the color spectrum and mixed them together, what color would they make?

I have been expecting a delivery of art supplies, so I was not surprised to find a small box from Dick Blick at the gate. I opened it to find a tube of oil paint inside, Torrit Grey, which I do not recall ordering. Then I saw that it is labeled "Always Complimentary Not for Sale". Thinking that my order must have been screwed up I checked the website and learned that the Gamblin company distributes this paint every year and that it is made up of the pigment that gets caught in their Torit filter system during the manufacturing process. Instead of throwing the pigment away they recycle it and make paint from it and give it away free to artists. The full explanation, including details on the Torrit Grey Painting Competition, can be found at the Gamblin website.