Well, I got a message back from a friend who used to work with the United Farm Workers:

"De Colores" is not a children's song. It's more like a song of nationalism, from Spain I think, originally. When Anglos write a song about the country, the place, the nation we love, it is more didactic...'we're the greatest'. Now a Latin poet will be more subtle -- THE FERTILE EARTH, the colors, the birds flying, a rainbow AND a FAMILY of chickens...a powerful pastoral symbol...EL GALLO (the strutting testosterone laden male fighter), the MOTHER HEN (the very symbol of womanhood, birthing, protective nurturing) and the BABIES....Oh, God, I love this!

Gringos write didactic prose; Latins write flowing poetry.

Furthermore, I believe "De Colores" was transported from Spain by the Roman Catholic Cursillo movement...very much connected to the advent and momentum of Roman Catholic reform in the 60s and onward.

Thanks.
-Joe Offer-