PSPUG Tutorial
Animated Rainbow
Tutorial found
HERE
Other experiments
#1
This was done like based on tutorial but using arrow from preset shapes instead of text and settings on inner bevel were increased.
#2
This was done as #1 except I used 2 layers. The first layer was white, and the second was my rainbow gradients with the blend mode at 50%..
#4
This was done with the same gradients using the circle from the selected shapes and the gradient set on circle. The order was also reversed from the tutorial.