Maraschino Cherries and Red Dye #40

Bright red maraschino cherries are colored with red dye #40 (E129 in Europe), as is Peychaud’s Bitters and other food and beverage ingredients.

Though there was some public worry about dyes causing hyperactivity in children, the United States FDA determined, "Although this hypothesis was popularized in the 1970's, results from studies on this issue either have been inconclusive, inconsistent, or difficult to interpret due to inadequacies in study design. " [link]

Some websites claim that this dye and others are linked to cancer, but this dye is not considered “toxic” nor banned as a food additive in the US or EU.

US Law

The United States FDA states [link], "FD&C Red No. 40 may be safely used for coloring foods (including dietary supplements) generally in amounts consistent with good manufacturing practice except that it may not be used to color foods for which standards of identity have been promulgated under section 401 of the act unless added color is authorized by such standards."

Certain color additives must be declared on certain beverages. This varies by country. 

FD&C Yellow #5

FD&C Yellow #5 [link]: " FD&C Yellow No. 5 may cause itching and hives in some people. This color additive is widely found in beverages, desserts, processed vegetables, drugs, makeup, and other products. FDA requires all products containing FD&C Yellow No. 5 to identify it on their labels so that consumers who are sensitive to the dye can avoid it. On medicine labels, this certified color additive is also identified by its uncertified name, "tartrazine.""

Further Reading:

"Allura Red AC" Wikipedia [link]

"How Safe are Color Additives?" US FDA [link]