If you look at marine pearl finishes they usually are a couple of layers. The "pearl" layer is actually very thin with just a milky white translucence to it. It's very thin yet gives the wrap it's pattern and "depth". The overall color is determined by the backing they laminate it to. White backing gives you white marine pearl, Black gives you Black diamond pearl and so on. The various "vintage" pearls will use an ivory or off white backing. Now if you laminate that layer onto a clear backing you can get whatever color(s) you want by painting back of the wrap or the shell itself. That's how these vintage drums were done. Also where some of the more rare marine pearl colors came from as they could do them in small runs.
I spoke to someone at Delmar about this and they said the clear backing style could still be done but there are minimum order amounts involved so that complicates things.
This is the way vintage ones were done. Modern "fades" have the colors applied via printer over the white base pearl. The Chinese pure cellulous acetate wraps are not laminated and the color runs all the way through them.
