Summary

A ghost that when printed in transparent filament can be put on top of a Smartibot board and illuminated using the RGB led 'eyes' on the board. Code to make the eyes fade between colours is here:
https://thecraftyrobot.net/blogs/projects/fun-diy-halloween-costumes#:~:text=var%20smarti%20%3D%20require(%22Smartibot%22)%3B