Food coloring does not expire, nor does it lose its coloring power. Food coloring should be kept well-sealed to prevent contamination from dust or other particles.
In the United States, the Federal Food and Drug Administration must approve the usage of all new color additives after they are tested and proven not to cause harmful effects when consumed. The FDA may still restrict the usage of food coloring in certain foods, even after the color additive is on its approved list. Due to the Nutrition Labeling and Education Act of 1990, any color additive used in food must be listed in the ingredients list by its common name.