In any animal, healthy or unhealthy, there are slight variations in the color of each poop. This is completely normal.
These variations are due primarily to how much time the stool spent in the digestive tract; how hydrated the donor was while they were digesting the food; and what the donor was fed at that particular meal.
We maintain strict quality control measures, but because the material in these capsules comes from healthy dogs and cats, and not from a synthetic source grown in a laboratory, slight variations in color are completely normal. We keep processing of the material at an absolute minimum in order to maximize the viability of the bacteria.