He inheirited white legs from his Orpington father because white legs are dominant over yellow. I have two Orp/BR same thing, white legs.
Bucky may be a sex link with a RIR, PR or NHR as the sire. BUT if his sire was the Barred Rock the other half could be just about anything as Cyn said. A Barred Rock father crossed over a whole bunch of different breeds would produce chicks that all look like that.
He looks to be a cross of a Barred Rock male over a Big red hen(RIR, NH, or Prod. red).
I've hatched out a bunch of these colored roos this is the original cross that Delawares were eventualy developed out of.
It's not a sex linkable cross as the males and females both are barred the males have the more yellowish-biege/sex feathers and the pullets are more cuckoo patterned than barred and are good layers of big eggs I might add.
The males make a nice table bird at about 6 mo. and really good gumbos from 12 wks. on.