An article in Food Safety Magazine, Colorants in Food Packaging: FDA Safety Requirements (Oct/Nov 2016), reviews the FDA safety requirements of food packaging colors and printing. In summary, "The rules of thumb for determining the regulatory status of a pigment or dye are as follows: A substance that colors the food, even if it is in a packaging material, is a color additive and may be used only as permitted by an applicable FDA color additive regulation. Substances that color only a packaging material, and do not impart color to the food, are regulated as food additives if components of the substance are found to migrate into food. No premarket clearance by FDA is required, however, if the substance is not reasonably expected to become a component of food, is GRAS or is included on the list of “pre-1958 colorants.”
There are always questions about printing on the primary packaging and what is the concern. So, the primary question is whether that printing material can migrate to the food. If it can, then that color needs to be approved for use.