Colour problem My 1220c will not print in correct colour it will only print in black & shades of purple

I think ur and my prob is same diff is my prob is completely solved if u want fix ur colour problem then follow this step
put ur catridge turn it and take a smoothe paper
and rub on it u find a colour of line means straight yellow redand blue colour in a straight line

if not then try this
Open the Maintenance tab by selecting:
- Start > Settings > Printers. Select the DocuPrint M750/M760 icon.
- Select Printer > Properties. Select the Paper/Output tab and click
on the Status button, then select the Maintenance tab.
- Select Clean… to display the Clean Print Head window.
- Select the black print head, color print head, or both, depending on
which you want to clean.
When you select Clean, the printer cleans the selected print head(s).
This button is disabled if neither head is checked."
This procedue may need to be repeated up to 3 times to restore full print quality.

If the automatic cleaning cycle does not fix the problem, try manually
cleaning the printheads:
"Remove the print heads and clean with a damp cloth. Use
a clean cloth, dampened only with water, to gently clean the
nozzles (the copper-colored area on the bottom of the print
head). When cleaning the color print heads, wipe the nozzles in
only one direction so that the colors do not mix."
(Xerox officially says to use water, but I have also heard of using
ispropyl alcohol. If you choose to try cleaning with isopropyl
alcohol as a last resort, you do so at your own risk.)

All information was obtained from the Xerox DocuPrint 750 Quick
Reference Guide, which was downloaded from the Xerox website.
http://www.xerox.com/downloads/usa/en/q/Qrefguide.pdf

If your printer is still not working, you should consider investing in
a new unit. The cost of repair (if even possible) will very likely
exceed the replacment cost.

Best of luck.

I recommend you change both ink cartridges. I have places a link below that may help you with this problem,
Thanks Sea Breeze

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00044516&lc=en&cc=us&dlc=en&product=316639&rule=41181&lang=en