Once again, the dye is ALREADY injected into their system. So ingestion by preening would be pretty inconsequential.
Colouring any new born animal is WRONG either way, I already know it can get threw there skin and into there bodies but not everyone understands that, some people think they won't get sick from eating it .. like idiots who die water red to attrack humming birds! Again when preening them selfs there just injecting more dye onto there system ON TOP of that they have already been infected from dye traveling threw there skin..