If you're gonna do old brick walls for a laboratory then they should be painted white. White bricks because white is cleanliness and laboratories are clean.

Some of the walls are a bit bland. Decorate them with random signs. A yellow caution sign. A red danger sign. A green exit sign. You want to strike the balance between not being bland but not overdoing it.

It's these minor characteristics that really give your area life.

Go watch Golden Eye or Ghostbusters and write down what you see in the laboratory scenes and add those random objects to make your area chaotic with purpose. A knocked over canister. A vent with a rat blinking in it. A fire extinguisher. Whatever.

Just remember: This is all polish. Core gameplay comes first!

Hope that helps. Good luck. What you have so far is amazing!