Without shaders, the default brick textures have white edges that glow in the dark. Same with Faces and Decals that use color. It's easy to see in the dark with these textures because the edges of all bricks literally glow. Without maps, everything is made of bricks so these textures are seen much more than before.
The game didn't become brighter, it just seems that way because there is no alternative to brick builds.
I suggest using custom brick textures.