When charging the meltdowner skill on my server, if I charge for too long (almost until or until it aborts) my screen becomes covered in something that slightly changes color based on light, and is yellow in daytime and black at night. My HUD is still visible, but I can't see anything in the world at all. However, this does not happen on a singleplayer world. Simply leaving the server and rejoining does not fix this issue, I have to completely restart my game.

When you reach overload, normally what happens is that OpenGL scripted shader starts flashing through your screen momentarily, and then returns to normal, to make it seem as if you're out of breath. It's likely conflicting with something. (also yes, that is one of the few instances an opengl script is called)
By conflicting I mean the same method is called and kept loaded in by something, keeping the things the way they are instead of making them return to normal.
Yellow and black is likely due to day and night. Both are odd, since the script creates a specific 'white' colored flash that is not affected by daytime in game.

Sorry, I'm not a programmer. I also haven't touched minecraft in a while, so my reply is a bit late