Cone 6: Cinnabar is a rich maroon-red gloss glaze that tends to develop a hazy purple float with heavier application. Cone 10: Color darkens. TIP: One to two coats will produce an opaque maroon-red; three+ coats will produce higher levels of purple float. You’ll produce beautiful color variations with Cinnabar without the glaze running off your ware during a cone 6 oxidation firing.