Made a few 18mm four hole pieces recently. This one is a Double Dipz, NS-Yellow over Dark Amethyst. This combo has been dubbed Deppe's Darkness by the community, one of those special pairings worthy of a name.
Definitely creates a unique electric purple I haven't ever achieved with other colors. It also happens to be the only reason I own any dark amethyst, which is just too dark for basically anything!