Seems like something from Ronnie James Dio (RIP)
I have never seen rainbows at night....
https://theultimatejeep.com/notfound.png
https://theultimatejeep.com/notfound.png
https://theultimatejeep.com/notfound.png
https://theultimatejeep.com/notfound.png
The sky was pretty dark and the sun was setting. The rainbow glowed.
This was erie!