Kralik Enigma - Reverse Flame

I'm a big fan of analyzing pieces to death and this one has been a mystery to me for a while. I finally got one to see for myself. I bid asking price because I knew It would just be seen as an overpriced Bambus, Pull or Flame decor... Its actually more complex than that.

It is clear in the handling of this piece that there are two layers and perhaps three. The base color is white (milk white) then there is a layer of bright golden yellow to cover the entire piece (like tango). A dark purple glass is then applied and pulled over the yellow and down to the foot- Rather than the yellow pulled up from the bottom! Finally there is a strong flash iridescent applied and fired into the piece in the furnace. After the making the piece they ground the top smooth and applied a gold mirror finish to it (this was probably re-fired to preserve the finish)

The mystery is: Is a yellow color involved or is the yellow produced by the white color being exposed to the iridescent acid? Only one way to find out- I'll either scratch the rim gold finish and analyze the layers of glass (like a fallen tree) or scratch the foot of the piece to expose yellow or white interior.

Any preferences?

P.s. These seem to be related to the single-colored mottled pieces (with the same gold rim)