used for the tubes, so higher concentrations are used to take the losses into account; higher argon content is used in higher-power tubes, as hotter glass adsorbs more argon. The argon changes the color of the "neon light", making it slightly more yellowish. The neon gas used in some nixie tubes includes a small amount of mercury vapor (for various reasons), which glows blue.

A Penning mixture of neon and argon is also used as a starter gas in sodium vapor lamps,