I might be wrong on this (probably am??) but I seem to recollect that the paint colour was the same colour as the interior trim.
There were exceptions such as if it was a green car with a green interior, then it had black or white paint in the hood strip. But for example a black car with a red interior it had a red painted strip.
I'm basing this on what a friend of mine was telling me back 30 years ago when he had a 55 or 56. Can't remember correctly what year it was.
