The "S" logo is clear green resin with light LED coming through underneath. *
It´s hard to capture the display with the camera as it looks alot nicer in real life.
Clear green? You are putting Superman on a Kryptonite base?! J/K - a clear white LED base would be also cool, just imagine in the dark!
Wasn't there a green crystal that Clark Kent carried to the North Pole and it was what made the Fortress of Solitude? its the main crystal that gave Superman all his knowledge and plays a big part in the first movie .