I built my first Stone Tower today, which didn't turn out quite like I expected to be honest... And unfortunately there is no way to preview this in the game. Even if you craft smaller structures like a stone throne, the texture isn't the same everywhere.
So maybe, with the painting skill, it could be possible to craft some paint from various stones, etc. and apply it on a previously built building to change its color? It could work like this:
You get the painting skill.
When you harvest a new type of rock, paint of that rock is added to the craftables.
You build a building, don't like its color, choose "paint" from the Build menu and place it on a building.
It requires varying amounts of paint depending on what building you're trying to apply it on.
You prepare the paint by maybe grinding some rocks (in quern lol?) and mix it with linseed oil (I have no idea here tbh) and then fill it onto the barrels and place it near the building site.
Start "building" the paint and the building changes color...
An expansion of this could be addition of new building textures that could only be acquired in a similiar way, like a brick textured tower maybe.