Actually it says the yellow and green are coloured with uranium, not the rose (pink) and radium; note that colours are paired. Without a butterfly, you'd be hard put to prove it was Hoffmann if it is not in the catalogue. I also didn't say Hoffmann didn't use uranium, just that I've never found any. I also think Pamela is wrong about the amethyst uranium; it is most likely manganese used as a colorant, particularly in that shade of purple; it would give a decent green glow.