Don't rush to give the most obvious answer - "pale green."

Yes, this is the most common color of Aurora, but there are other shades. The glow occurs due to the collision of charged particles with atoms in the upper atmosphere.

The color of the glow depends on which particles collide: 💚 pale green or scarlet - collision of electrons with oxygen atoms

💜 purple - collision of electrons with nitrogen atoms.

The saturation of color and its warmth may vary depending on the height of the radiance (the lower, the more saturated) and third-party factors. For example, light pollution in a city can turn green shades into turquoise.