Monocrome is fine.
Colors only gets me 5 tiny and pale lines printed on the sheet.
I compiled the latest (2007-07-18) drivers and reinstalled them.
Deleted printers, recreated, etc.
I verified I do have *DefaultColorMode: Color in my ppd file.
I restarted cupsys, rebooted, etc...
Would you need specific logs or info?
Forum: HP Color LaserJet 1600