Scourge Wings Paint Scheme

I am finally painting some scourge wings and am deciding I want to do them awesome. I remember seeing some time ago a rainbow type color of wings where each layer was a different color (green, red, blue or something like that). I'm trying to find that again or something similar to it that I can steal and use as inspiration for the wings paint scheme. Any help would be appreciated greatly. Below is the model ( a corsair psycher to be).