The US FDA doesn't allow for any dyes on products (humans or animals) to be unspecified. Petco is a US company, therefore they
must list all dyes and products used to create the toys/chews. If they don't comply (or the supplier company) they will remove the product and either require listing or will take it down permanently. Besides that, vegetable dye is safe as is
https://www.fda.gov/forindustry/colo...lperspectives/