None of those are foods. They are ultraprocessed food-like products developed in chemistry labs.

Skittles ingredients:

SUGAR, CORN SYRUP, HYDROGENATED PALM KERNEL OIL; LESS THAN 2% OF: CITRIC ACID, TAPIOCA DEXTRIN, MODIFIED CORN STARCH, NATURAL AND ARTIFICIAL FLAVORS, COLORS (RED 40 LAKE, YELLOW 5 LAKE, BLUE 2 LAKE, YELLOW 6 LAKE, TITANIUM DIOXIDE, BLUE 1 LAKE, YELLOW 6, RED 40, YELLOW 5, BLUE 1), SODIUM CITRATE, CARNAUBA WAX.

None of those are found in nature.