Below is a statement on behalf of the FDA:
FDA conducted an extensive safety review of the scientific studies on FD&C Yellow No. 5 and FD&C Yellow No. 6. Reviews of the critical safety studies for both food colors were used to establish the current acceptable intake levels. FDA requires labeling of FD&C Yellow No. 5 under the list of ingredients as it may cause allergy-like symptoms in a small subset of the population. In addition, the law requires that most foods containing a certified color additive (such as these colors) declare the color additive as an ingredient by name on the product label, providing consumers with information about the use of these colors in their food.