None of the material colors that inventor 2013 actually look like what they say. White in gray, any polished stainless also a gray color. Is it posible to copy the styles library from 2009 into 2013?
Try modifying your lighting style. The default lighting style is Two Lights, and one of these lights is set to a bluish gray color. Change the color to white-- gray becomes white again! You might also bump up the Ambience setting under All Standard Lights while you're at it.