Not your fault. You didn't know but at least you feel guilty about it. Some people just shrug it off and go "they're fish, who cares?" Most people start out not realizing some of the stuff done to fish to sell them.
Dyeing fish is on the wane as well I think. There haven't been as many dyed fish in the various stores I've been into lately but it could just be a regional thing too.
Some are aware but do it anyways because the more colorful looking fish tend to sell better. Those that don't may think twice about it next time. One can only hope. The LFS I spent most of my time at only has them on occasion but they tend to keep the natural looking fish. People usually don't appreciate being "had" when they learn their brightly colored fish is going to get a duller or darker coloration anyhow.
