How to do that?
How to make a part of board a ghost board?

You can ask me or any other CGA to make it.

technically you can do it if you find in settings> wall color and set it to just the right color for you the walls will be transparent (:
There is a way. Go to a game with already transparent walls(ex. Colosseum) and click "Edit position". Then when you press "clear board" and drag a wall onto the board, it will become transparent.

There is a way. Go to a game with already transparent walls(ex. Colosseum) and click "Edit position". Then when you press "clear board" and drag a wall onto the board, it will become transparent.
That doesn't work, only CGA's can change it permanently - after you save the position, exit the website, and a few days late you come back, the wall will have changed to the standard settings
actually, it will always work until you play/edit a position with opaque walls.
How to make a part of board a ghost board? Like The Colosseum?