You can recolor it; the stone textures are in DDS format in the models folder. You can open them in Paint.NET or Photoshop.
Here's my "original" texture in PDN format (I don't know if you can open it in Photoshop; this format is used by the Paint.NET program). The trick is in the layers: the first layer is the yellow stone of the monument, and the second layer is the colored stone, which you can safely recolor without damaging the first layer.
So, in principle, if I take any texture (well, not just any, but hypothetically), cut out part of the objects onto a new layer, recolor the layer, and save it, will that result in a "safe recoloring"?
Interesting, thank you. I probably won't be coloring anything else, but I'll experiment with it in my free time.
Будь яростней пред ночью всех ночей,
Не дай погаснуть свету своему!
Хоть мудрый знает – не осилишь тьму
Во мгле словами не зажжёшь лучей –
Не уходи безропотно во тьму.