Ammeter to Voltmeter...who does it?

On my 67, with the "tint" (aging?) of the plastic face, the color and difference of the needle is barely noticable. Hell, I've got a friend who's "traitored" over to GM from Mopar and I said "take a good look at that ammeter." this was with the key off and so it was pegged to the left with no voltage. I had to 'splain it to 'im he "didn't get it."