Color Confusion

I am hoping someone can help me. My 65 Barracuda is currently a silver color this was a repaint before the early 80's. I have done some work and taken some of the paint off and there is blue with seems to match medium blue. I went through the paperwork given to me tonight and I found several things. I found the Bill of Sale to the second owner stating the car had never been wrecked. I found the certicard with a Paint code of NN1 which seems to indicate Silver. Is it possible that the dealer repainted the car? Would the certicard have been issued with a different color? I am confused because I see no silver below the blue.