Create a magical rainbow color flame in Photoshop

Create a magical rainbow color flame in Photoshop | Veerle's blog: "One of the things I’ve seen around quite a bit lately is a transparent rainbow gradient effect on a dark background. It seems to me that flashy transparent gradients are in these days. They make me think about magic. Today I’ll show you how you can create a magical rainbow color flame. OK, maybe I’m using too many words in a row here, but it’s the best I can do to describe this."