Tinted Curing Mix

I'm writing lessons about making sausages and other cured meat products. I would like to use some of the recipe from "Garde Manger" by the C.I.A.
Tinted curing mix is used in a lot of the recipe, but I don't know what that is and cannot find it in New Zealand, where I live. Can anybody provide me with an ingredients list of this product or an alternative.
Is it a sodium nitrate or saltpetre mixture?

Thanks Tony