So you're saying that the printer...

- Used to print your color photos well, in the past?
- Suddenly it started printing your photos all pale and washed-out?
- The printer test page contains color photos, and the test page still prints them well?

Is that correct? If true, it's definitely some driver or configuration setting. Outside chance that it's a setting on the printer's front panel, but more likely in the windows printer controls. Since the physical part of the printer is still fine, as proven by the test page.

Many color printers have a "draft mode" or "preview mode" or "economy mode" which prints in lower resolution and saves ink by using less of it. That's what it's looking like to me. Since you said the picture is also printing in low rez, I'm thinking this is the likeliest possibility.

Outside chance that it has a setting to print photos with just CMY and leaving out the K, though not sure. I think that's less likely than draft mode.

Another possibility is that you changed the paper setting in the configuration. Some printers will change the amount of ink or toner that they deposit, based on the type of paper you told them you were inserting. For instance, if you tell them you are using photo paper, but insert plain paper, the prints will come out lighter.

Another possibility is that the printer has a gamma setting for printing photos, and that got tweaked.

And of course if you are using photo paper, make sure you're printing on the correct side, a mistake I once made and posted about here on the BBS. Though my failure mode looked completely different.