I was mixing up big batches of a premix and portioning it into 1/4 cup balls. That way I could give the JRT 1 ball and the Border Collies 4 balls. I had the same experience as you. The fresher it was the pinker it was, the older it was the grayer it was. One day I was lazy and just stuffed 1 lb containers full and put lids on them. They all stayed pink. Not only that, but I lost one of those containers in the back of the freezer and found it about 9 months later. It was still pink and fresh looking. The difference? The balls were stored with air all around them, the 1 lb containers were completely full, so no air in the container. I went out and bought more containers of the right size.
