Here is a posting you might want to read and see if it might help.

http://forums.us.dell.com/supportforums/board/message?board.id=A940&message.id=15290

Thanks.  I read that and did try to clean the cartridge, but it still doesn't work.  When I hold the paper towel against the print heads, I do see color, but when I try to print, the color part doesn't work at all. Do you think it's the printer? 

I too am having the same problem. Intalled a brand new printer cartridge and the color wont print. Tried reloading the drivers and soaking the print head in hot water and pat it dry on a paper towel. I see color on the towel but will still not print in color. Dont know what else to do?