I’m quite proud of this method! A few years back I was attempting to create an iridescent shader that included customizable colors and a bright fresnel, but none of the methods floating around seemed to fit my various criteria. Going back and forth to import new color gradient texture images was a bit of a pain as well.
There are no texture maps needed for the iridescence, as it uses an atlas curve and linear color curve to create the color gradient. You don’t need to keep editing any image gradients outside of unreal, and you’re not limited to two colors.
The user can also stack transparent textures on top for extra details. 
