KALEIDOSCOPE 3

As promised here is the 3rd part to my mini-series KALEIDOSCOPE. 

This is something I came up with accidentally while working with KALEIDOSCOPE 2. I'm happy with the final result and glad to share with the Forum!

There are two discs of arrow shapes rotating in opposite directions with smooth & *random* colour transitions of the arrows. Only four colours: red, green, blue and yellow are used for a better visual experience. The only reason for the second disc is to show that colour change is independent of distance from center of rotation and amount of discs. Any (reasonable) amount of discs would fit the existing pattern.

A Challenge:
Can you try explaining how I made the smooth & *random* colour transitions?

Suggestion 1:
Select 1 arrow and follow it for a longer time.
Suggestion 2:
Observe only 1 of the discs. 

*random* is not really random only pseudo-random because animation follows the same pattern initiated by the start position. It gets hectic after that and very quickly impossible to predict.

The download link to the .ppsx file is here.

If curious about how I made the effect, KALEIDOSCOPE 4 will present a stripped-down version of KALEIDOSCOPE 3 to reveal the behind-the-scenes "mechanism". Stay tuned!