One recommendation I've run across (don't recall where) is print a color image once a week. It doesn't need to be a very big print, around the size of a color comic in the newspaper. You only need to get fresh ink into the print head nozzles.
Here is what works for color matching:
You will need a colorimeter, a Color Target Card, a scanner, a printer, and a CD reader.
IIRC, either the Color Target Card had software available, or the early Spyder colorimeters included, software to generate color correction tables for all three output devices.
1. Calibrate the display
2. Get a standard Color Target Card with calibration files (mine is from
http://coloraid.de)
3. Scan the Color Target Card and generate/install the cal. file for the scanner
4. Scan the Color Target Card again and print it
5. Scan the print you just made and generate/install the cal. file for the printer
Be aware that different ink suppliers often have noticably different colors; although that seems to have improved over the years. Also, visible ink colors can differ under different lighting conditions.
Obviously, I've left out the details - it's been years since I've bothered. I did have to replace my scanner recently so I may be forced to re-learn those details!
Cheers,
Tom
p.s. I have sometimes gone 2+ weeks without color printing, the head is sometimes clogged at that interval. If a second head cleaning doesn't clear things up, wait a day and try again - that will often work.
At around 2 months, replace the print head. As a last-ditch effort, you can try removing the head and soaking it in Ammonia. However Ammonia is corrosive enough that if it is not well flushed out, the head will corrode internally and soon die anyhow. By the way, Ammonia is good at removing ink from your hands, it is rather drying though.