Yellow 6 (officially Sunset Yellow FCF, FD&C Yellow No. 6) is the orange-yellow dye behind bright cheese snacks, orange candy, some "cheddar" mac and cheese, sodas, and citrus-flavored drinks. It's frequently paired with Yellow 5 to hit the exact orange manufacturers want. The FDA has certified Yellow 6 as safe for general food use and, like Yellow 5, considers it one of the more heavily used synthetic dyes in the US food supply.
The kid-specific concern comes from the same evidence base as the other dyes. Yellow 6 was one of the six dyes in the 2007 UK Southampton study that linked a synthetic-dye mixture to increased hyperactivity in 3- and 8/9-year-old children — the study that pushed the EU to require a warning label on dye-containing products. Yellow 6 is on California's AB 2316 school-food ban list (effective December 31, 2027) and appears on the EWG Dirty Dozen Food Chemicals list. The AAP 2018 policy statement flags synthetic dyes, Yellow 6 included, as worth limiting for kids.
In everyday shopping, Yellow 6 clusters in the bright-orange snack aisle: cheese crackers, cheese puffs, "extra cheesy" mac and cheese, orange sodas, and orange/yellow candy. The dye-free versions of most of these now exist — Annie's cheddar snacks, for example, use annatto and paprika for color instead of Yellow 5/6. Defaulting to those SKUs is the simplest way to cut exposure.
How to spot it on a label: Yellow 6 appears as "Yellow 6," "Sunset Yellow FCF," "FD&C Yellow No. 6," or the EU code E110. In the EU, products with Yellow 6 carry the warning "may have an adverse effect on activity and attention in children," which is why many European versions of the same snacks use natural colorants. USDA Organic products cannot contain it.