This tileable texture has been blocked out in Maya, sculpted in ZBrush, baked with MightyBake and textured with Phtoshop.
The color variation for the night window is done directly in Unreal multiplying a color on top of the original window color. More details about the material here: https://www.artstation.com/artwork/Gbwr4
As all my other textures the Photoshop file is pretty modular (through the use of Masks and Adjustment Layers) allowing me to easily change and adjust many different properties of the textures: Albedo, Normal and SRM (Specular, Roughness and Metallic channel packed texture).
I usually pack and export my textures in Photoshop taking advantage of the amazing "Expresso" exporter: https://minifloppy.it/portfolio/expresso/
Marmoset Viewer - Windows - Nighttime | Daylight