I found this on oldchevytrucks dot com but it dont say what color blue.
1965 Truck 230 Blue
Here is a link to some Pontiac Engine Colors
http://fiedlerh.home.att.net/enginecolor.htm
and truck engine colors
http://www.1954advance-design.com/Web%20images/PPIP/PPIP-1912-1966-EngineColors.html


250 Integrated Head / 1981 C-10 Pick up.