Zebra ZXP Series 7 IX Series YMCKOK Color Ribbon 750 Images/roll. The ribbon is used to print in a variety of colors: yellow (Y), magenta (M), cyan (C), and black (K). The remaining overlay (O) provides an extra layer of protection for the card. The second (K) allows for printing in black on the back side of the card. The ribbon is used to print on both sides of the card.