Rainbow chicks at the bird market (Yogyakarta, Indonesia)
Here is how to make colored chicks: Take 3-day old chicks (youger chicks would not survive the treatment, from what i heard). Plunge them into a color dye bath. The chicks are then sold as a live toy for children, for a few thousand rupiahs a piece (i.e. less that 1 dollar), and kids love it. Not sure that the chicks appreciate the treatment, but they don't seem to care much.
Colored chicks are apparently very popular in Indonesia, I have seen them at several village markets around the country.