According to Sandhill this is a difficult request to honor. From their site: "Partridge Penedescenca: Their color is slightly variable with the females being marked similar to a Light Brown Leghorn. The males are more variable in color but resemble slightly the Light Brown Leghorn male in color. Leg color varies from slate blue to off-white. They are rather large fowl with an extremely nervous temperament. They have varying degrees of the typical Penedescenca comb which is a single comb with a crown at the back. Our primary method of selection is for the darkest egg possible. Too many double yolked eggs makes chick supply poor. Chicks $7.00 each (5) (SOLD OUT THROUGH May 2, 2017)"
I know there are breeders on this site though- many carrying black or crele. ChickenCanoe is one of the breeders you might want to contact.