You don't know the half of it. They have to actually removed the protective slime from the fish before either injecting, or adding the dye. I don't know every single way they do it, but some ways they actually dip the fish in some kind of acid. The silly thing is, the dye wears off after a while so you will actually end up with a drab looking fish. We try and advise people not to buy these type of fish. It is totally inhumane to do this to any creature. If I know of anyone who does this to fish, they will certainly get a mention on this website, and so will their business.
I'm not aware that it's been banned, it certainly should be