The interior walls should not be black (even being outside the rooms), or the garbage and rotten food on the ground or bed in the room.
In the graphics options, did you try changing the Darkness setting to 50, and bump up the gamma a little, to see if that would make a difference?
If you didn't reboot at some point during your troubleshooting, try doing that. As you may have already seen in topics where the other suggestions were made, I eventually run into a similar problem with DD and BD (inside or at night) if I leave my computer on continuously.
In the Steam discussion Rainbow Lighting Bug
the OP said setting the alphabit to 0 fixed a black texture problem (after XP compatibility got rid of the rainbows). That isn't an option in the BD configuration file though, so I assume they edited the line in the BD config.div file ('Alpha bit 0').
If the line isn't there to edit, you can add it, but make sure it isn't the last line in the file, as the game expects that to be blank, so ignores it (as was probably mentioned for the rgb edit).