The following quote from the Image-Resource test of the K10D confirms my own experience with the my K10D.
"The Pentax K10D showed really excellent color accuracy overall, holding strong reds more in check than almost any other camera we've encountered. Its greatest color error was a hue shift of medium-orange toward yellow, but even that was relatively slight. Average saturation was 108.6% (over saturated by 8.6%, largely in the reds, but somewhat in the blues as well); average "delta-E" color error was 302 after correction for saturation, the most accurate color rendition we've ever tested, if memory serves me. All in all, unusually accurate color, among the best we've seen. (Some consumers may find its strictly accurate rendering less vibrant than that of some other cameras, but pros should welcome this level of accuracy in their work.)"
Test Link:
Pentax K10D Digital Camera - Full Review
As an old Kodachrome 25 shooter, I am having to re-learn my past lessons with that film......expose for the high lights. If the high lights are kept in control, I amazed at how much shadow depth can be extracted from the PEF raw file.