http://www.dxomark.com/Cameras/Pentax/K-S1
Worst than the 16M Pentax bodies? But it has more pixel counts. So, if this benchmark is just not practical enough, you can see some real-world tests and samples, for instance, below:
http://www.yaotomi.co.jp/blog/walk/2014/09/pentax-k-s1-review-first.html
http://www.yaotomi.co.jp/blog/walk/2014/09/-pentax-k-s1-review-second.html
http://www.yaotomi.co.jp/blog/walk/2014/10/-2014-pentax-k-s1-review-third.html
(in Japanese)
Or, if the colour depth is yet not enough, Pentaxians can yet get more colours of the body, look at these! ;-D
http://www.ricoh-imaging.co.jp/japan/campaign/20141023/