Screen -> Darker

I know, the title is AWESOME.
No, but seriously.

Could anyone tell me how I would make the screen of everyone in the map go darker?
Like… Fade it a bit.
I bet this question has been asked before, but I couldn’t find a thread, so well, I made one.

Anyone who can help me out a bit?
By the way, not a weather mod, but like a script.

Thanks.

I would go for this: http://wiki.garrysmod.com/?title=G.DrawColorModify
But I never tried it so… don’t know if it works like you want…

Yeah i confirm that’s what you need.