Xenon (Xe) in plasma

Xenon burns white with a faint lavender edge, and it is the workhorse buffer gas behind most of the doped vessels in this collection. Its emission is spread thinly across the whole visible range, which is exactly why it reads as white rather than as a colour.

Xe at 15 torr is a typical fill for generic toroidal plasma flasks. Pure white color that runs at very low power inputs (like 30-50W) and is perfect for large flasks as buffer

Periodic Table of Plasma