Yeah, when you're trying to select wall and floor colors in build mode, it can be a bit dark. What I do is just keep adding light fixtures until the room lightens up enough for me tell what it really looks like. I move them around too if I need to. When I've gotten things the way I want them to be, then I just delete any lighting fixtures that I don't need for live mode. Adding windows temporarily helps sometimes too, to give you more light to work by. And I find that using the afternoon setting works better for me for most of my builds.
Hope this helps.
This is what it looks is that what yours looks like too?
The only way it goes back light is if I click on one of the walls and I make it a half wall
What you are seeing is normal. I see the same thing when I use the room tool to make a room or use the wall tool to make a room. The darkness comes from no outside light being in the room as it is fully enclosed by walls, floor and ceiling. There is another thing you can do to lighten a space while you build. Select the room like you have done in your pic. Go up a level and click on the yellow outline and delete the ceiling while you work. When you're done with the room, put the ceiling back. That won't work if you have a room above though.
Hope this helps.
