Color printer full will only print black in my

You have a cartridge problem.

This condition is typically caused by one of the cartridges failing. Try removing the black cartridge and printing (not copying) a test page. If this prints at near normal speed the black cartridge is at fault and should be replaced. If the printer still prints slowly then put the black cartridge back in and remove the color cartridge, then print a page. Replacing the cartridge that causes the slow printing with a fresh cartridge will resolve the issue.

apply the following; after you done pressing into the PRINT button click first the MAINTENANCE button then click again the PRINT TEST PAGE button, then kindly and patiently do the procedures over and over again until the test print paper will resume to its normal color and functions..in that way the black and color cartridges will be recognize in that kind of procedures..in that way your problem has been solved already...

Here's the official HP solution for what you're experiencing. If you try all the steps suggested and you still have a problem, remember that you can contact HP for warranty support for the cartridges you've purchased - even if your printer is out of warranty.
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00721052&cc=us&lc=en&dlc=en&product=1153494
One thing I'd try first is to print a self-test page. If you print a self-test page and the colors appear normal, you can rule out the iMac as the source of the problem.
The instructions for printing a self-test page are similar to the c7280 shown in the following video.
(do not delete)
I am an HP employee. I do not represent HP on this site.

Did you try to wipe the cartridge.Maybe there's a clogs. inside.

Hey, Sound like something is wrong with the color cartridge. Replace the color one and try again. If that fails you might have to replace the printer as it doesn't sound like the problem is software related.

Try this test:
Let's say you want to print this present page (of fixya.com from Firefox or another web-browser), try File/Print and see if you have the tab Advanced to change to the color cartridge.

Go here. In the search box in the center of the screen, type "print with black ink only" and click Search. Choose the appropriate link, and you will get instructions for printing from either Windows or Mac.

u better try this ,remove color catridge from the printer,switchoff n switch it again with black catridge only,the printer will give catridge error dont worry ,n try to print any black font document from the printer n see does it print black,n reply
thnx

Please make sure that the cartridge of the printer is not and working properly. You can test it form sending a test page to the printer form printer properties. If the test page is all right then check the application (which you are using) properties for color print and the default print properties of the printer. Hope the problem will solve if the cartridge is ok and not dry.

I just got off the HP help line.  After changing my black ink cartridge a test page was printing each time I turned the machine on.  This is very costly, in both time and ink as the cartridges themselves for this machine hold very little ink.  I tried to learn from HP tech how to turn off the test-print while keeping my color cartridge empty.  It turns out that you cant do it.  HP requires you to keep buying and using cartridges whether you need them or not.If you buy the color ink it will use it up in its testings.  And if you dont buy the color cartridge it will use up your black ink by printing the test each time you turn on the printer.  The printer was inexpensive sure, but I'm paying for it in wasted ink.