So it only on the preview?  Or does he render oddly metallic?  The preview will look very different from the rendered result most often.  I have Jeremy, and when loaded, he is very  shiny in preview but renders as expected (somewhat lackluster IMHO).  The Poser materials for him are a bit shiny regardless even rendered, they need tweaking at very minimum, better to scrap the included shader entirely and use VSS.  But that is a separate matter entirely.

Remember, the Jeremy promos on Daz were rendered in DS and use the EHSS setup for him.  He does render differently with the included material set up in Poser.