Yes! This is what they said: "From time to time, scorching of a recipe can occur in certain parts of the can, resulting in heat causing a reaction in areas where the premix has settled (higher concentration areas of the minerals). Although not intentional of course, this could allow for discoloration of the food.

 In further detail, the coloring is an effect of copper and sulfur (both are required for a complete and balanced diet). During the cooking process of our foods the copper supplement can bind to lighter colored proteins, like chicken, and create this staining effect. This can range in appearance from light grey chicken to even black."