You can apply material types (colors) if you open up the part. Then if you look at the top of the screen (at the quick-access toolbar) there is the material type drop down bar. If it is not on your quick-access tool bar it is under the view tab(i think it is that tab in the ribbon?)
Also, for magiccode, this is a great library with all the parts and everything, but they just need to be more organized. Similar to Apertures and 24’s would be great with the folder organization.
But how can I be complaining because I didn’t post one!
All the parts should be colored realistically. Are you viewing the parts with “realistic shading” and with ray tracing enabled?
Also, the library was made in Inventor 2012 Pro Student Version, and is not guaranteed to work in any other version. As I did not personally make the library, if you have questions or comments, please direct them to the support site listed above.