I picked this wall lamp as an example.
Group 0 is dropshadow, and Group 1 is whole objects having Phong shader.
I’m going to change group 1 to recolorable glass. If you want to leave one Phong group and added new glass group, duplicate group 1 and change new group 2 into glass.
Material setting is done.
Replace textures with your own as usual, and test it in game.
Textures are not shown in TSRWS preview, you can see only in game.
Here is in-game shot of this example lamp.