Colored Chicks to Order, 1947

      Frankly, we didn’t believe it either. But the evidence looks pretty convincing. It seems that down in San Juan, Puerto Rico, a certain experimental-minded senor named A. R. Zeno injected two dozen eggs with various vegetable dyes two hours before hatching time. When the chicks broke through their shells they were peeping happily and were apparently quite normal except that their feathers were bright blue, red, green, pink and lilac. And here they are as they arrived by Pan American air express eight hours later in New York City.

Easter chicks dyed a variety of bright colors several hours prior to hatching.
 The coloring wears away within a few days; it is harmless to the chicks.

Colored chicks are still for sale during Easter in some countries. 

My mother remembers receiving a few of these in her Easter 

basket just after WWII.