Cone 6: Cordovan develops a deep, burgundy red color with a semi-gloss surface when fired to cone 5 or 6. Cordovan produces a brick or iron red on white and red midrange clay bodies. Cone 10: Color changes to a dark metallic gray with copper/black mottling. TIP: Two coats should be plenty to get deep red, opaque coverage; light glazers may need to add a third coat.