I don't believe so...at least they're not supposed to. Someone on here was sold a different breed by accident. I personally just bought a Jersey Giant that has grown into an Australorp. It happens when you're hatching out a variety of different birds all at once. Do you have a picture you can post?
I haven't seen any with dark legs either and I got really carried away with sticking eggs in the incubator. All the chicks have yellow legs.