New HP Officejet 7500A wide format inkjet multi-function printer. OS 10.8.2. Connected via ethernet cable to a Belkin N750DB wireless router.

Everything a/b this machine is superb except for one little glitch that even an hour on the phone with tech support couldn't solve:

The printer's touch screen provides a "Scan to Computer" (or walk-up scan) option, which means I can drop an original on the glass or the ADF, and select the format I want my scan saved in. But, if I choose PDF, the final is always grayscale. Other formats (like jpg) scan in color. And scanning to PDF from the desktop, with the HP utility or VueScan, results in color. I have run through every setting on the Mac and the printer's onboard settings, too.

The tech had me uninstall the software, delete any related prefs, and re-install, plus a firmware update. Still no joy. Scan to Computer as PDF still yields only grayscale.

This is not a hill to die on for me, because walk-up scanning is not something I would do as a rule, and scanning from the desktop is problem-free. But, if anyone has any ideas, I'd like to hear 'em.

TIA.
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