I made some gifs of one of my younger fortresses:
(https://i.imgur.com/O9L0T9F.gif)
This is the cavern level, with diorite as the layer stone, which made the hallways indiscernable. The smattering of teal to the left is cavern vegetation.
(https://i.imgur.com/B1qcTQ1.gif)
Main bedroom complex. You can see how smoothing stone changes the color and makes it impossible to discern wall from floor.
(https://i.imgur.com/KKcl3hQ.gif)
Orthoclase bridge to a nearby mountain.
In a sufficiently complex fortress, I imagine this tileset would create beautiful and interesting visuals! Though, as you mentioned, it's impossible to tell what's going on.