I dont know if chocolate is in the U.S. But it could have been moved into another breed and be here. Also, some genetic combinations can look like something they are not. I dont think that blue roo is a chocolate. He may be brown red based under it all and it is just some red pigment bleeding thru. I believe its best to have silver underneathe a black than red. Since blue is a diluter in itself , I would suspect that the roo is just showing some bleeding to give a brownish cast to his dark area. But there are some other diluting genes that could be causing it. But for a show quality blue color that bleeding would be a defect in the show room as they want that black over lay to realy have a contrast against the blue. Spanish andalusions are good examples of that type of blue. Depends on the breeds standard , some breed want a smooth even blue like a lavender colored chicken.
Steve