yes that is what I used this is only one of them the rest are movable

Well, it doesn't make sense to be used like the way it is in the image, but cubes have an output called OnPainted (I think) that triggers an output when it is covered in any type of gel. That's how Fluppy managed to create the gel converter in the Space Gardens map pack.

I don't quite understand that. you paint the half-cube and turn things on/off ??

At my map have i used too
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=189686554

see what happens in the first room
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=189638846