The Slate was accepted by the American Poultry Association in 1874.  The Slate or Blue Slate variety is named for its color, which is solid to ashy blue over the entire body. The flecks throughout are to be black.  White and rusty brown markings may be present but are considered a defect.

Hens are lighter in hue than the toms. The head, throat, and wattles are red to bluish white. The beak is horn in color; the eyes are brown; and the beard is black. The shanks and toes are pink. The Standard weight for a young tom is 23 pounds and 14 pounds for a young hen.