Experimental #56 Siriusly is our newest formula of the CFL colors we are producing currently. Northstar will continue to produce and improve this glass so it can graduate into our palette and be available at distributors. This glass is both flame and color stable, and will present a deep teal green in natural light and then shifts to a vibrant purple in a CFL. Air content varies with this color. For best results, use a 2700K (kelvin) CFL bulb as well as using this glass in thicker applications. This glass contains a small amount of copper, use an oxidizing flame for best results.