Riding my Motorbike
This may help a little on what we see here on the decal. Multi-colored decals are built up in layers. Each color is a 'run' much like silk screening. The layers are extremely thin and measurement is in 'mils'(a decal's layer thickness/measurement for thin-somewhat like sheet metal which is measured in gauge). To keep the same color of the decal on different colored bikes it is necessary to have a common 'base color'(under the original gold color) which is what we see here as 'white'. This base color will reflect the same gold color on the down tube and other decals as well-long after the gold has rubbed off-especially after 75 years of use/abuse and exposure to the elements. Below is an example of the first and probably the thinnest layer rubbing/wearing away and the other areas where there are multiple layers 'surviving'. Nice project Eddie!