The Hallway colors are pretty good. I do recommend that you should use Diamond Plate on the walls for it better.
The floor and design is pretty good. I also suggest that you should make signs or a custom GUI map for the players not get lost in where they are going.
I know this was very long ago but please don’t reply to this. This was made when I was really bad at building. Here’s the newest version: SCP LCZ Hallways. Thank you.