The skin and meat of corn-fed chicken is more yellow, a result of having been fed corn or maize. The colour fades on cooking, but the meat is juicier and has a richer, fuller flavour. 
 
Corn fed chicken have more flavour and are easily recognized by their yellow flesh. In 1589 King Henri IV promised the French people that every family would have a chicken in the pot on Sunday's - this is the chicken they would have wanted to eat!