Final answer:
The most widely used food color in North America is FD&C Red No. 40, known for its vibrant red color and cost-effectiveness.
Step-by-step explanation:
The most widely used food color in North America is FD&C Red No. 40. This artificial coloring, also known as Allura Red AC, imparts a red shade to foods and is favored for its intense and uniform coloration, stability, and cost-effectiveness. Colors like FD&C Yellow No. 5 and FD&C Yellow No. 6 are also commonly used, but Red No. 40 is the most prevalent among the artificial colorings that are permitted in the United States.