I'd go with Ponitac blue, not because I'm concerned whether or not it's origional; rather, I'm free to pick and choose as what I deem correct and incorrect.

There is nothing wrong with clashing clors; in fact, clashing colors were a trademark of the era.

Just because a Pontiac blue engine is correct for me, it doesn't mean it's correct for you. If something is correct for me, I don' have to ask someone else whether or not it's correct for me. If a color change is correct for you, you shouldn't have any problems making the correct decision.

Heck if I did was correct for my car, the correct thing would have been to junk it, so other's people version of correct isn't always the correct decision that you must make.