The above was first tested out with my K-5, of which the hue output was always not correct for most of my Pentax digital lenses for all of the built-in custom image profiles, even for the Natural profile, which was supposed to be colour accurate. So, I sat down to think what's wrong and observed quite some of my old photos made with the K-5..
My conclusion was that green colours are lacking yellow. Skin tones are lacking red, orange colours could contain more red. Thus and therefore I made the above hue shift. Btw, the most unfortunate thing is that no official documentation could ever tell the user what are the actual effect and meaning for changing this setting! >:-o Nonetheless, one drawback of the above is Blue colours now contain more green, thus they could be more cyanish. But the factory defaults are too blueish for many things anyway!
Still, two obvious problems with the Natural mode is the lower contrast and saturation for most lenses and shooting situations and thus I bumped up both for 1 step. As for the sharpness, I found that the standard Sharpening method (parameter set) is yet the best and 1 step up will make the JPEG directly out of camera to be more usable, while balancing well with both sharpening artifacts and noise.
On the other hand, I noticed that some Pentax users said that the K-5 series bodies are a bit cool for the AWB. But actually I don't find the same. The AWB is accurate but the problem primitively lies with the wrong hue shift. In order to verify this, just set the camera in preset white balance in particular the daylight WB and then shoot under sunlight, this can be proven and confirmed, example test here. For instance, that is something like what they set:
So, the ABOVE is NOT recommended! The incorrect hue shift will not be completed corrected but yet new yellow cast will be introduced for quite some situations. After all, my recommendation is to leave the AWB at default settings, ONLY changing the colour profile is needed and will work.
With the same optimal colour profile used with my K-5, I put it into my Q and it still works like a charm! :-D
After all, I would not post any of my sample images this time. Just try it out yourself to see if it is better or much better and things have actually improved! :-) And, I am always happy to share even everything could just be "useless as usual", as what my haters and fanboys said! ;-p