Mods, I couldn't find a better place to post my question, so my apologies if I posted in the wrong section, please feel free to move this threat to a more appropriate forum as you see fit.

I'm using Numenor's modding info center post "THE "PARTITIONS": WALLS, FENCES, FENCE ARCHES" http://www.modthesims2.com/showthread.php?t=106473 as a guideline to modify the behavior of one of his custom walls.

I changed the blocking light behavior to "blocksLight false". This command did achieve the effect I want, when using the custom wall, the indoor lighting is the same as outdoor as if the walls didn't exist. However, the custom wall itself is significantly brighter than a normal wall. The difference apparent when a wallpaper is applied (see the picture).

My question is if this is supposed to be this way or I made some mistakes in the configurations, and the custom wall can in fact not block light and not turn into a bright wall itself. Thanks in advance if anyone can help.

This is the full configuration that's I'm using for Numenor's invisible wall.

#invisible wall
wall 91
defaultPattern "blank"
wallThickness standard
mayChangeSurface true
mayAttachObjects true
mayCutAway true
requiresFlatBottom true
requiresFlatTop false
submersible true
verticalSpan floorToFloor
blocksLight false
blocksPlacement true
deleteTool partition
thumbnailResource 0 0x499db772 0xE9261340
thumbnailResource 1 0x499db772 0xe9261347
thumbnailResource 2 0x499db772 0xfeed5515
thumbnailResource 3 0x499db772 0xfeed5510
catalogTextIndices 0 1 2 3

It looks like the "sun light" were in all "directions" but the shadows remained. Because of the "extra brightness" on white colors.

If it's what you want. I think it's supposed

I don't think this is something that can be corrected. The brightness of the wall is not generated by an "additional brightness" contained in a Material Definition, but by the "lack of shadow" affecting the entire wall section. The outdoor shadows are hardcoded in the game and can't be modified.
the only workaround I can suggest is to use the same wall type for the entire wall (or at least from corner to corner, so to minimize the visual difference).