Print the kryptonite.stl with transparent or translucent filament, green, transparent or natural (PLA) should be perfect. I used PET for my print, it was the only transparent filament I had. Grey filament for the rocky base and if you so desire, print one of the inserts (the second one is ticker, to make for a darker green and easier to slice) in a green color and place it on the inside of the crystal, this should allow for a bit of green to shine through if you decide to use transparent filament. Most tea lights, at least those that I have, are yellow, so the green insert helps insure that the kryptonite stays greenish.