Nice render, Jura. You shouldn't need to mess with colour if you are lighting with HDR, as the colours are taken from the image. I haven't been using HDR, just a jpg on a skydome and using Poser infinites, and they seem to look better if you sample either the skydome jpg (blue) or the floor/walls material.

Just to restate/clarify my original reason for posting, it was the discovery/realisation that Poser/Firefly behaves similary to film. To put that another way, to achieve what might be considered a linear progression in tone requires an exponential progression in both light and ambient. BB stated that he used 'aggresive' settings, but my realisation is that they are not aggressive, but appropriate.