I get what you mean. Most rooms don't use the same rocky textures in the foreground and background, like I did here. This room is a little offshoot, tucked away semi-secretly, so I wanted it to feel more like a much more enclosed space.
I've been adjusting the brightness of the background and dimmed it just a bit more. Whether it's enough of a difference for anybody to notice except me is anyone's guess, though.
I'm not a designer at all, but as a player I honestly don't think that it blends in too much - Instead, it adds to the kind of "gloomy" feel of the room (Dark colors + not a 100% easy to discern some elements = Acts a bit like a dark room)
Not sure if I managed to say what I wanted to say, but you get me