Unfortunately once it's done, it's done...usually when they're still in their eggs to boot. Eventually the dye will get removed when they molt, very few keep a bit for long periods before it fades away(occasionally the coloring on the heads takes longer, but usually not). Just take good care of them. The cruelty is in how and why they do it, it endangers the baby in the egg when they dye it, and are sold to people with kids who get bored once the colors fade and no longer care for them. So just give them proper care. You can get them checked by a vet if you're worried about them though. =)

If hair dye was actually used on them after they were born, then they do need immediate vet attention, but likely it was done while they were still int he egg and should not have any adverse affects on them now if they're showing no issues, and if you take as good of care of them as it sounds like you will.

You can't really do much, dye stays. I'm speaking from inexperience here but I'm guessing that dye stays in feathers much like human hair. If it's a temporary hair dye, then it may wash out soon as few brightly coloured hair dyes are permanent, but apart from that you'll just have to wait for the chicks to shed those feathers which in all reality shouldn't take too long.

I bought these poor chickens this way, a Mexican in a garage looking barn was selling baby Chicks and I have a rooster that I ADORE and I figured I would buy a few babies. I bought 5 and all of this guys chicks were colorful (green, red, pink, orange, etc.) anyways, how do I get this dye off? it isn't cute to me, it looks like a baby was tortured with hair dye to please children on Easter.. should I just let feathers grow in? when they get wet hopping in their water despenser the dye does NOT come off. I have had them for about 9days. Help?