What is the legal ruling on consuming food products that are said to contain pork derivatives as coloring agents (such as yellow 5), without definitive proof of that?

The basic principle regarding foodstuffs is that they are permissible, and they are not rendered unlawful by doubt. The statements of those who source these messages should be accepted if they are trustworthy; otherwise, they should not. For some may speak without knowledge or with ill intent to cause people hardship.