Color is associated with type of atom and the altitude it is at. The process is the same as a neon sign. The electron is excited into a higher orbital shell and when it falls back to its ground state it emits light.

This is from memory but close:

Oxygen above 180 miles emits red. Below 180 miles it is green to yellowish. This is because above 180 miles it is atomic oxygen and below it is molecular oxygen. Nitrogen can be blue to red, can mix into violet, and is lower in the atmosphere but still above 60 miles. If you have ever been in the high latitudes and seen an auroral sheet it can be greenish yellow near the top and red to blue to violet on the bottom.

Im not sure how pink is formed, I do know it happens but only very rarely. Helium and Hydrogen only occur very high up in the exosphere above 350 miles. The human eye cant see this aurora.

Color is associated with type of atom and the altitude it is at. The process is the same as a neon sign. The electron is excited into a higher orbital shell and when it falls back to its ground state it emits light.

This is from memory but close:

Oxygen above 180 miles emits red. Below 180 miles it is green to yellowish. This is because above 180 miles it is atomic oxygen and below it is molecular oxygen. Nitrogen can be blue to red, can mix into violet, and is lower in the atmosphere but still above 60 miles. If you have ever been in the high latitudes and seen an auroral sheet it can be greenish yellow near the top and red to blue to violet on the bottom.

Im not sure how pink is formed but I do know it happens but only very rarely. Helium and Hydrogen only occur very high up in the exosphere above 350 miles. The human eye cant see this aurora.

Color is associated with type of atom and the altitude it is at. The process is the same as a neon sign. The electron is excited into a higher orbital shell and when it falls back to its ground state it emits light.

This is from memory but close:

Oxygen above 180 miles emits red. Below 180 miles it is green to yellowish. Nitrogen can be blue to red, can mix into violet, and is lower in the atmosphere but still above 60 miles. If you have ever been in the high latitudes and seen an auroral sheet it can be greenish yellow near the top and red to blue to violet on the bottom.

Im not sure how pink is formed but I do know it happens but only very rarely.