Advertising signs can be illuminated by running an electrical current through a sealed gas tube. This type of sign is typically referred to as a "neon" sign. Why is this name often incorrect?

 

This is often incorrect due to other gasses being used not only neon. The neon gas produces orange light, hydrogen gives off red, helium releases yellow, mercury for blue and carbon dioxide emits white. The color of the light relies on what gas in on the gas tube. Therefore, it is a frequent misconception and often times people use shortcuts to describe objects and phenomena. In the 90's, George Claude utilized Moore tubes that requires nitrogen and carbon dioxide to give off light so he often envisioned that this type of light will be used in the future.