My feeling is that it was a non metallic paint.
Speaking of metallic vs non metallic colors, if you look at the standard paint chips from '68-'69 at least, I've noticed that all of the metallic colors use the word 'Poly' in the naming...but...notice that Windward Blue was one of the special codes for '68 and it does not use that word. If you look at a '69 paint chip card when Windward was a standard color, it is called Windward Blue Poly.... So does that mean they added the metallic as it became a production color or did they just not use the word Poly when it was a special color?
http://thefirstgensite.com/library/p...ntiac-pg01.jpg