Three colors generally.
The main color is green, then blue and finally red. It depends on what gas is involved and how high in the ionosphere the reaction takes place.
- Oxygen gives off green light usually, or sometimes browny-red.
- Nitrogen gives off blue or red.
- If the collisions take place high up then oxygen gives off red. Lower down oxygen gives green and nitrogen shines blue and red. Lower down still oxygen is quiet and nitrogen still gives off blue and red.
Pink,Green,Yellow,Orange and a violet colour
