The color or variety is "Light Brown". The light brown will be the wild type color pattern with the males being black with light brown hackles and saddles and the females being light brown with the salmon breast. The standard for Dutch Bantams is Slate Shanks for all the varieties except the Crele and Cuckoo varieties due to the diluting effect of the barring gene that creates those varieties. If you are getting yellow or white shanks then you don't have pure breed Dutch. They have likely been out crossed with something else along the way.