The colored chicks is much less popular now than it was a while back, it was a really big trend about 15 years ago, but it is still something that people do. Not so sure what the point of it is, but It's much more a rural than urban area thing, so people just keep the chicks on the farm afterwards I assume.
I know one farm where they inject the dye into the eggs so that when they hatch they are already colored, it only lasts as long as the first feathers though so they grow out of it and back to normal color really quick.