The difference in color of the neon tube is dependent on the amount of other gasses in the tube. When there is a little extra "other" gas in a neon tube it will be a little less bright and a little more pink.
The difference in color of the neon tube is dependent on the amount of other gasses in the tube. When there is a little extra "other" gas in a neon tube it will be a little less bright and a little more pink.