I brought the brightness of the photo up for sure here so that it looks interesting and not dim/dull on your display.

I can tell you from experience though that we were able to see the red, blue, violet, green, and sometimes the yellow on the horizon unaided. Put simply, it was incredible and I wanted this photo to provide the same feeling.

Here’s a photo I transferred to my phone with the transfer app doing a simple jpeg conversion. 2.5 second exposure at ISO 5000, 36mm:

This is perhaps slightly brighter than what I recall seeing on the horizon.