I've been working with my Kyocera SL300R for over a year now. Like many reviewers I have been concerned with the high contrast and dark shadows on this camera.. I have creataed a couple of color pofiles that lighten up the images considerably. If you are interested in using them or making your own profiles more information is available here.
From what I have seen SL400R owners will benefit from these profiels as well. I don't think they will work for the Contax SL300RT though.