When viewing older GM cars and trucks we see both colors of park light lenses. There seems to be no consistency that gives us the proof of what is actually correct, however, it is easy as remembering a year.
Beginning in 1963, the Department of Transportation new federal regulations required park lights to show an amber color, to be seen easier in fog. Today, companies reproducing original clear lenses find it easy to run more in the same die using an amber additive. As GM had already planned for the clear lens through 1966, it was no problem to add amber die to the plastic and they were in compliance.
Therefore, for early GM trucks most reproduction clear lenses are now marketed in amber. It is the buyer’s choice.
One exception is the 1969-1970 Chevrolet truck. Originally all came new with clear lenses but behind them are amber park light bulbs giving the required amber color appearance when illuminated.
