This is my Lihtopane created from photo of Marvel Avengers(also attached).
It is a first version, and I am going to update it :-)
Fillamentum, Fillament PM PLA
You will need a piece of plexi glass to attach at the back of the sign, some LED strips, connectors, switch and PSU/adapter.
To connect the red parts together I used the connector.stl to have better area to put on glue, but if you can do it without these, no problem.