This is very similar to the previous post but I didn't realize I was replicating until it was done. I wanted a rainbow gradient but there was a point to the greenery and the flowing red river. When I remember what that is...I'll let you know.
There is something wonderful about the rainbow. While it might have only seven distinct colours, the in-betweens are full to the brim of some of the most amazing shades of colour. I do not know if I will ever be able to fully reproduce it, but the attempt is worth it in every way.