http://zeldaclassic.armageddongames.net/viewquest.php?q=318
Zap warp from a lit room to a dim room and the room will be pitch dark instead of dim.
You can see this for yourself in the easy 6th dungeon, go left, up, bomb the block then push one up. You will be warped to a new room. Take the return warp.
I mean.
(the wavy one when using a portal in the 3rd Zelda game (SNES))
Zap warp from a bright room to a dim room and the whole screen will be black except the subscreen and enemy/character sprites.
Verified...
I have a pretty good feeling this would be fixed as it hasn't been bumped in eons.
Should be working right now.