Some time ago my other half (who is not fish-orientated) bought some 'pink' widows and 'blue' widows for our aquarium (I already have black widows). It seems these are actually white skirt tetras which have been injected with dye. No doubt the people who did it thought they needed brightening up, and upped the price while they were at it!
The problem is, these fish are not happy. They constantly nip each other, and the black ones nip them too, and several of them have sustained damage, like missing pectoral fins or a missing eye. Fortunately, I have plenty of room in the tank, so they can keep away from each other most of the time. I assume that, since fish communicate by colour, each of these poor fish sees the others as some kind of alien, so instead of shoaling peacefully they're all afraid of each other!
I am very tempted to euthanise the lot of them, because although they're not suffering physically as far as I can see, they must be suffering mentally. I really think that dyed fish should be made illegal, and the people who sell them prosecuted. Surely fish should be protected by the RSPCA against this kind of cruelty?