Nice composition Tom. Colours don't look that far out to me, but when I bought my K10D I read the review at:
DCRP Review: Pentax K10D
The reviewer felt that the default settings on the camera gave dull colours/soft pictures and recommended adjusting settings to Contast: +1, Sharpness: +2, and if you personally felt it appropriate Saturation: +1. I have changed my settings in line with this. I don't know if it is still relevant as there has probably been a firmware change since the review was done. I don't know if firmware changes affect these kind of issues. It would be interesting to know if others have modified these settings and what their experience has been or if they have felt the default settings were ok.
Paul