Now that I have the bowl and have taken some photos, trying to show the finish. The bowl actually has a light green inner and clear glass (not a white inner vendors description). The colours appear to be floating above the green inner and cast a shadow on the green inner. I have captured on image 1 the shadow (letter S stands for shadow). Image 2 shows the tool marks when making the whorls in the glass, these marks can be felt with my finger as can most of the coloured whorls.
Gary