just of give my 2ct, Laurie might have her own reasons (and will kick in, I'm sure).

the pale cyan I know is present in mainly the early V4 skins, in Diffuse that is. It takes out a bit of red, which is re-added in via the ambient and alt_diffuse channels. As a result it fakes a subsurface scattering on caucasian skin in Poser renders, without the rendertime costs (and in times SSS was not around at all).

Due to the way gamma correction works in PoserPro2010/12/... (and from May 21 on, in P10 as well :-) ) this fake effects turns into the well known unhealthy long term smoking vampire skin as the cyannic effect is enhanced.

More on this in my tutorial on Gamma and Corrections http://www.book.artbeeweb.nl/?p=317

And of course you're right, most people don't have a good clue how a metal really looks like. But some people do. On the other hand, a lot of people will get some mental clue when it's off even when they can't tell why. In my opinion, making (alt) specular the same color as reflectuon is clue in metal as it colors the reflection, and Poser specular is just the reflection of the direct lights as Poser reflection is the reflection of all surfaces, lit in a direct or indirect way. Adding both up completes the scene.

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Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though