no mod. its done with Ice. I discovered it completely by accident on Alliance Armada's old starmade server when I found myself in need of a base, but not much in the way of supplies except the remains of a consumed ice planet before my salvage ship died.
Basically just place desired colored light blocks on the ends, or behind, or against the ice, and it will lightly diffuse the light down the length of the ice like maybe 5 blocks or so? so if you take a Rammet crystal and plunk it on one end and then a mattise an plunk 'em on the other end of say a 10-15 block rod of ice, it'll get an effect like the red/purple i use a lot of. the semi transparancy makes them very pretty visual fluff, or even interior lighting. and it depensd on the posistion of the sun, if your looking towards the sun you get the beautiful colored semi transparent effects, if your looking at your ship with the sun behind you, it gives it a multi-hued opaque sorta.... stained glass effect.
