Updated version for 1.6
Content
Adds 3 new Walls in Gloomy Style. Sterile, Reinforced and Reinforced with Embrasures.

Sterile Wall
This Wall costs 15 Silver and 5 of the Building Material you choose.
They have a Cleanliness Rating of 0.6.
You need to research "Sterile Materials" to build them.

Reinforced Wall
This Wall costs 5 Steel and 15 of the Building Material you choose.
They have more Hitpoints. Blast resistant.
You need to research "Reinforced Gloomy Walls" to build them.

Reinforced Wall (Embrasured)
Same costs and stats as the Reinforced Wall
Provides 70% Cover
You need to research "Reinforced Gloomy Walls" to build them.
*Walls will change their color according to the materials you used. The pictures are just examples.
Credit
Based on the work of Primus
MoreGloomyWalls (no longer updated)
Other Gloomy Mods
Gloomy Furniture
Gloomy Deco
Gloomy Embrasure (Reworked)