The colored shells are from Arucana or Araucana chickens..they are from south america. http://www.feathersite.com/Poultry/CGA/Arau/BRKAraucanas.html

There is a French breed called Marans whose egtg shells are very dark
brown, almost burgundy or chocolate colored.
http://www.sdeggs.com/maransdescription.html
http://www.mcmurrayhatchery.com/product/cuckoo_maran.html
http://www.mcmurrayhatchery.com/category/standard_breed_chicks.html

some fighting cocks are fitted with silver spurs beware--if you
google cock fight you might find some sites with no chickens in them.
Music thread...Tom Russell has a great song about a fighting rooster
called Gallo de Cielo.
Juni Fisher has a sequel to it called Ghost of El Ciello