My triple blue '67 convert (Tyrol Blue exterior) had a black frame. It was black and only black in every nook and cranny after being stripped of the top. I find it highly unlikely by '70s bodyshop standards (of which I worked under) that a frame would be completely stripped prior to a color change. I also find it unlikely that the only color changes were from black to blue. Hence, I tend to believe there were some blue frames.
On a side note, some of the Camaro guys claim their converts did NOT come with a coat hook while have yet to see a Firebird frame without one.
