67 barracuda numbers

I did notice something interesting on the fender tag. It has an upper door frame color u which is a y on my tag which decodes to medium gold. The interior was tan from the factory, but changed to black later. The yellow I am talking about doesn't really look like a medium gold and the yellow appears in the door jambs (under plugs) and under the strike plate in the trunk so far. The yellow also looks like that pale yellow that they used to paint these cars. This is all interesting and I would like to know what I have here.