How to disable the glowing of the doors?

[Googolplex]

What file did you edit googol?

That makes me wonder if the level doors were saved as a note type, but set not interactable, and had a script over them, in which case, it's not a directly new shader, but a neat trick. The only way I could imagine to change them would be to replace the door models in the files with the normal ones. But that might be a pain in the butt.

Open the file "...redist\shaders\game_object_flash_frag.glsl"
And change the rim light from 1.0 to 0.0.
You can even experiment with values like 0.5, but either the notes are too dark or the doors too bright.