What I meant was: there look to be three passes of colour (probably the black, 'bronze' and blue in that order), using different silk screens, so it might be possible to see how the colour was built up. Naturally, the more passes of printing, the more expensive it was to produce, and the more likely that it could be rejected due to errors. So they are not that common.
That's why I value the earlier colour screen-printed ones over the colour transfer-prints.